There are too many individual questions in here that I don't really know where to start with you in a non-consult situation.
That said, you're 20, not grossly underweight (but still underweight), still on LP, and have no baseline for your nutrition.
My recommendation would be to slowly gain weight, track your macros, and look at your college experience as a time in your life where you have almost unlimited time to train, because it is. You have to prioritize and this is hard work to do, but college is chill from a time perspective.