Re clothing and other issued items: anything you have been issued is yours. But, as part of outprocessing, you'll get a brief on what is yours and what is the U.S. Government's, how to turn in the latter, what your options are with the former. You might see whether classmates are interested in uniform items, especially since yours are still in excellent condition.
Look, no one can tell you what it's going to be like when you get home. Your home is a unique set of experiences and people with histories, opinions, beliefs, and so on. The only thing you can choose about it all is what you think and how you react. I originally wrote, and several others have also mentioned, that YOU have to decide what your narrative is. You also need to have a plan, because even if you had the luxury of sitting at home on your a$$, playing XBox and eating Doritos, it won't take you long to sink into depression resulting from no purpose. Even if you get a minimum wage job at McDonald's, do SOMETHING. Have a plan. (Incidentally, you're capable of more than McD's.)
As for whether to bail now or later. Please listen to me; I am a college professor, and colleges do too care about your grades, even if they're all C's. That is college credit you earned. YOU EARNED IT. And you did it at one of the most academically-challenging, rigorous colleges in the world. If you're that close to earning credit, why on earth would you, in effect, burn the last three months of hard work? So they're not great grades; welcome to what happens to 65% of college freshmen in this country - two out of three of you take a hit of (on average) 1.2 grade points in your first semester in college. It's called adjusting to demands of college. (And incidentally, your instructors may indeed suck at USMMA, but one expectation about which many or most college freshmen experience a severe and shocking adjustment is the degree to which we hold you responsible for your learning. But that's another topic.)
None of us can do this for you, but we're trying to make it easier. In the long run, it will be easier to tough out the first trimester, actually COMPLETE something, and bail clean. You will leave with college credit and with the EVIDENCE that you can begin and complete something very, very difficult.