The title of your thread is about being healthy. You have any reasons to think you're maybe not healthy? Because if there are issues that are making you 'unhealthy', that's most likely where you get your 'health' back from.what should i be focusing on? discipline? expressing myself? not being so shy? like what am i supposed to be workin on over here?
The questions you have in your posts sound more like they're about becoming 'stronger', not so much about becoming more 'healthy'.
So yah, I'd go with what @ForsakenMe says, work on your issues to become healthy, then you can work on your strengths as an INFP (Fi, Ne mainly) and see what you can improve about yourself to complement your strengths, which would probably something like developing 'use' of other functions.
Also, don't be disappointed if things don't go as fast as you'd like to. It takes years to strengthen your personality, and not all things are under your control, or not as much as you'd like them to be. ^^