Randomnity's questions about identifying a direction are good. I would recommend also that you ask yourself why you want to be a scientist -- what aspects of scientific work interest or intrigue you. Is it hands-on experimentation, predicting outcomes through models, understanding fundamental properties of the universe, designing things and making them work? Another way of putting it: just what do you envision yourself doing all day as a scientist? Answers to these will also help you determine not only what kinds of courses to take, but what kinds of research experiences to look for.
Do not be put off by math. First, you probably are more capable here than you think. Second, there are many fields and subfields of science, and they vary in how math-intensive they are. Third, contrary to (some) stereotypes, few scientists operate as the Lone Ranger. Most work in teams where something that is not your strong suit will be a strength of someone else, while you have some strength that they lack.
If you are interested in science, do not let anything, especially not your MBTI type, deter you. Yes, depending on your field you may run into more INTJs than you otherwise would. Just keep being yourself, doing a good job, and the variety will actually be quite welcome.