tsdesigner- your advice has some merit to it, but you don't understand infjs at all. you just say they are wrong without showing the way from where he is to where he could go. you just want him to become an intj bc you think intjs are better. nope. wrong.
i like what usehername says but the ultimatum may or may not be helpful at this point either. it takes a while to get it sorted out. i find the best approach in this situation outlined a few times throughout the thread is to just make some positive steps. stop worrying about solving your broken life, your view of yourself, the world, everything. you can't do it holistically, it can't happen with one single move or one N idea that reframes everything. there are pieces that, if shifted, will show you the puzzle better, but the puzzle is always (and always will be) the puzzle.
for starters you sound like a ton of other infjs, it's not a new unsolvable problem. you're just fixated and pretty judgy (not that this is a bad thing). you use extraverted judgment really harshly on the world around you and have not learned to balance the internal external pressure (on yourself vs on the world/others). i've found that finding works of art that express my own internal contradictions help me deal with my contradictions in judging the world around me, others, etc. but that's a long process. but it's something to work on.
in the meantime, the only answer is letting go more. accepting a FAR HIGHER RATE OF FAILURE. you have to accept negative situations and negative circumstances more easily and let them go. you have to suspend judgment more often, realize that even tho you may not be comfortable with something or it may violate your ideas, understandings, values, Ni picture of what the world should be like, it may have a validity (read: value) of its own that you are not yet aware of. you don't know everything. god, i fucking was so judgy when i was younger and i would just reject EVERYTHING in one fell swoop. i would not allow myself to learn how to play any of the games bc i would JUDGE them immediately from a pre-conceived notion and reject the whole of the experiences contained within them as false or contrived or arbitrary.
like relationships. meeting people in ways that FELT false, cheesy, disgusting, pathetic, etc. people with what i perceived to be no real or lasting or valuable connection. but i only saw a very limited range of how the game could be played, what it could consist of, and most of all the rewards in learning how to play it for yourself and for/with others. being pleasantly surprised is step 1, opening yourself enough so that that can happen for you. yes the process feels random unless you strategize, and you may only meet a slow trickle of people related to your friend's brother or your classmate's _____ or etc. and it may be something cheesy like meeting a book club to get to know new people but, in my experience, the people who accept the conditions of the game, accept the world around them for what it is, who try to make the best of it, end up living far better lives. social experience rounds a person out, gives them better information to work with (if they know smart people and can think critically), and it gives them positive feedback and social support. it helps a person understand him/herself better, especially as an infj, borrowing the eyes of others but not fixating to one particular interpretation (tho if you find that home for yourself, by all means, it feels pretty damn good).
this is all necessary in teh process of understanding yourself better, clarifying (read: testing) your values, discovering what is important to you and what skills you possess. you may feel minimized at first when around others and under-appreciated, but sometimes it takes a lot of fucking games of musical chairs before things line up and you find the right situation (or two or three etc). you know mbti. N folks help, seriously, understanding this basic quality of perception makes it WAYYYY easier to explain social success and failure. it makes it so much easier to see basic patterns and shapes in social activity that will become more and more maneuverable with a bit of practice.
it doesn't matter if something seems arbitrary at first if it works. effects and side effects spew out in all directions, many of them create much of the richness of life for us, regardless of how they work or why they work. we are what we are, the world is what it is, and you are what you are. but you can evolve in a positive way. and you can help improve what is around you with different attitude and more perspective(s). and you can enjoy and participate in the world that is here all around us.
dead-ends still open up some doors. i met one of my friends in an aborted attempt at a culinary degree (i was there as a hobby), in which we both dropped the class by the third session bc it was too painfully retarded. we were the smart geeky N kids so we immediately became friends. such is life.