Ok, first off, stop taking tests. You keep getting different results and it's only confusing you more. Start with the mental functions go from there. Look at the definition of each one and pick which one you prefer or have a tendency to do most. I have taken the liberty of posting some good descriptions of each of the mental functions.
Eight Mental Functions
“Sensing is a process of becoming aware of sensory information and often involves responding to that sensory information without any judgment or evaluation of it. Sensory information is concrete and tangible in nature. In the Sensing process, the focus is on the actual experience, the facts and the data. As an active perceptual process, it is more than stimulation of the five senses. It is the registration of that stimulation and actively being drawn outward to the concrete realities of a situation or inward to recollections of familiar experiences.”4
Extraverted Sensing – “Experiencing and noticing the physical world, scanning for visible reactions and relevant data. You are one with the experience. There is no "naming" or describing - just pure, vivid experience. The whole scene comes into your awareness almost at once. You may be drawn to experience more and more, seeking any variation that will intensely excite the senses. Writing that is richly descriptive can also evoke extraverted Sensing as can other mental stimulation. The process is momentary and tied to the events of the immediate situation. It is used in the here and now and helps us know what is really there in the physical world and to adapt to it. Extraverted Sensing occurs when we scan for information that is relevant to our interests, and then we mentally register data and facts such as baseball statistics, the locations of all the restaurants in town, or the names of all the actors in the popular television shows. There can be an active seeking of more and more input to get the whole picture until all sources of input have been exhausted or something else captures our attention. Associated behaviors include eating a whole box of chocolates for the variety of tastes; playing an instrument for hours with pure enjoyment, not for practice; voracious reading or continual asking of questions to get specifics.”4
Introverted Sensing – “Recalling past experiences, remembering detailed data and what it is linked to. Introverted Sensing often involves storing data and information, then comparing and contrasting the current stimulation with similar ones. The immediate experience or words are instantly linked with the prior experiences and one registers that there is a similarity or a difference - for example, noticing that some food doesn't taste the same and is saltier than it usually is. Introverted Sensing is also operating when you see someone who reminds you of someone else. Sometimes the feeling-tone associated with the recalled image comes into your awareness along with the information itself. Then the image can be so strong, your body responds as if reliving the experience. This could be seen as a source of feelings of nostalgia or longing for the way things were. In one instance, a young couple living in Europe spent their weekends trying out restaurants looking for food that tasted like American food.”4
“Intuiting is a process of becoming aware of abstract information, like symbols, conceptual patterns, and meanings. It is an intangible "knowing" of what something means, how it relates to something else, or what might happen. Some call this the "sixth" sense. Sometimes this process is by an external event, or sometimes this abstract information just seems to present itself to our awareness.”4
Extraverted iNtuition – “Inferring relationships, noticing threads of meaning, and scanning for what could be. Extraverted iNtuiting involves seeing things "as if" with various possible ways of representing reality. Using this process, we can hold many different ideas, thoughts, beliefs, and meanings in our minds at once with the possibility that they are all true. This is like weaving themes and "threads" together. We don't know the weave until a thought thread appears or is drawn out in the interaction with a previous one. Thus there is often an emergent quality to using this process. A strategy or concept emerges based on the here-and-now interactions, not appearing as a whole beforehand. Extraverted iNtuiting involves realizing that there is always another view. An example is when you listen to one friend tell about an argument and understand perfectly and then listen to another friend tell a contradictory story and understand that view also. Then you wonder what the real story is because there are always so many different possible meanings.”4
Introverted iNtuition – “Foreseeing implications, conceptualizing, and having images of the future or profound meaning. Introverted iNtuiting often involves a sense of what will be. The details might be a little fuzzy, but when you tune in to this process, there is some sense of how things will be. Using this process, we often are able to get pictures about the future or at least a sense of what will happen before we have any data. Sometimes it is an awareness of what is happening in another location and we have no sensory data to go on. Other times introverted iNtuiting operates when we conceptualize and get a sense of a whole plan, pattern, theory, or explanation. These are the kinds of images that come to us in the shower, in meditative states, or in dreams and help us deeply understand something. Sometimes they are profoundly symbolic and even universally so. In using this process, we tune into a likely future or something universal. This information can then be used to decide what to do next, what to plan for. Introverted iNtuiting involves synthesizing the seemingly paradoxical or contradictory, which takes a problem or situation to a new level. Using this process, we can have moments when a completely new, un-imagined realization comes to us. There is a disengagement from interactions in the room, followed by a sudden "aha!" or "that's it!" kind of experience. These kinds of experiences are often seen as if they are "psychic" in nature. The senses of the future and the realizations that come from introverted iNtuiting have sureness to them and an imperative quality that seems to demand action.”4
“Thinking is a process of evaluating and making judgments based on objective criteria. Using this process, we detach ourselves from our values and seek to make decisions based on principles. Activities like discriminating according to a set of criteria or objectively defined standards, analysis according to a set of principles, logic, and cause-effect reasoning are all examples of using the cognitive process of Thinking.”4
Extraverted Thinking – “Organizing, segmenting, sorting, and applying logic and criteria. Contingency planning, scheduling, and quantifying utilize the process of extraverted Thinking. Extraverted Thinking helps us organize our environment and ideas through charts, tables, graphs, flow charts, outlines, and so on. One woman labeled the shoeboxes for her 100 pairs of shoes for color, height, style, and comfort. Sometimes the organizing of extraverted Thinking is more abstract, like a logical argument that is made to "rearrange" someone else's thinking process! An example is when we point out logical consequences and say, "If your do this, then that will happen." In written or verbal communication, extraverted Thinking helps us easily follow someone else's logic, sequence, or organization. It also helps us notice when something is missing, like when someone says he or she is going to talk about four topics and talks about only three. In general, it allows us to compartmentalize many aspects of our lives so we can do what is necessary to accomplish our objectives.”4
Introverted Thinking – “Analyzing, categorizing, and figuring out how something works. Introverted Thinking often involves finding just the right word to clearly express an idea concisely, crisply, and to the point. Using introverted Thinking is like having an internal sense of the essential qualities of something, noticing the fine distinctions that make it what it is and then naming it. It also involves an internal reasoning process of deriving subcategories of classes and sub-principles of general principles. These can then be used in problem solving, analysis, and refining of a product or an idea. This process is evidenced in behaviors like taking things or ideas apart to figure out how they work. The analysis involves looking at different sides of an issue and seeing where there is inconsistency. In so doing, there is a search for a "leverage point" that will fix problems with the least amount of effort or damage to the system.”4
“Feeling is a process of making evaluations based on what is important, where personal, interpersonal, or universal values serve as guideposts. Using the cognitive process of Feeling, situations and information are assessed subjectively. The impact on people, circumstances, appropriateness, harmony, likes, and dislikes are all considered in making Feeling judgments. Weighing different values, considering ethical and moral issues, attending to personal and relationship goals, and having a belief in something all involve this process.”4
Extraverted Feeling – “Considering others and responding to them. The extraverted Feeling process is used in relation to particular people and situations and so has a more here-and-now quality than a universal, future, or past quality. When particular people are out of our presence or awareness, we can then adjust to new people or situations. This process helps us "grease the wheels" of social interaction. Often, the process of extraverted Feeling seems to involve a desire to connect with (or disconnect from) others and is often evidenced by expressions of warmth (or displeasure) and self-disclosure. The "social graces" such as being polite, being nice, being friendly, being considerate, and being appropriate often revolve around the process of extraverted Feeling. Associated behaviors might include remembering birthdays, finding just the right card for a person and selecting a gift based on what a person likes. Keeping in touch, laughing at jokes when others laugh, and trying to get people to act kindly to each other also involves extraverted Feeling. Using this process, we respond according to expressed or even unexpressed wants and needs of others. We may ask people what they want or need or self-disclose to prompt them to talk more about themselves. This often sparks conversation and lets us know more about them so we can better adjust our behavior to them.”4
Introverted Feeling – “Evaluating importance and maintaining congruence. It is often hard to put words to the values used to make introverted Feeling judgments since they are often associated with images and feeling-tones more than words. As a cognitive process, it often serves as a filter for information that matches what is valued and wanted. We engage in the process of introverted Feeling when a value is compromised and we think, "Sometimes, some things just have to be said." On the other hand, most of the time this process works "in private" and is seldom expressed directly. Actions often speak louder than words. This process helps us know when people are being fake or insincere or if they are basically good. It is like having an internal sense of the "essence" of a person or a project, and reading another person or action or project with fine distinctions among feeling-tones. When the other person's values and beliefs are congruent with our own, we are inclined to feel kinship with them and want to connect with them.”4
4www.geocities.com
Simplicity is key, I suppose. 
