I'm so sorry you're having such moodswings. I know how terrible moodswings can be. -.-
I think you should try to cope with all the stressful things that you listed. Perhaps make a list of things that you could try to make everything feel better? For example, you're leaving your friends and family behind in the US - call and message them as much as possible and remind yourself that you'll see them again soon. You have to live with people you barely know - you can comfort yourself in that this is a rare and great experience and you'll be able to meet some new, interesting people that may turn out to be your best friends eventually.
You wrote a list of 5 stressors; try to make a list of positive things to cancel out the negative ones. Try to remember that this is a valuable and unusual experience that you've been blessed to have, and that you'll learn many things from it & you'll be back at home and enjoying normal life soon enough. But for now you should embrace your current situation and make the best of it. I hope that everything turns out well for you!