For the love of God, get some earplugs. People in dorms/halls don't care if you're not sleeping well. Go to a hardware store or anywhere that does home DIY stuff and get a bag of those bright orange earplugs that construction workers use. It will stop you from having to kill your new friends. Failing that, screaming "shut the f*ck up" louder than their music also seems to work, but should only be used in emergencies.

E: Also, if you get one bad night's sleep, don't worry too much about it. Experience has taught me that you can live a couple of days on crappy sleep - yes, even you. I know you're thinking "not ME, I NEED my 10 hours!" but honestly, the mental sluggishness is all in your head. There's no use lying awake thinking you'll never get to sleep and therefore you will have a bad time in the morning. You will be ok and you should go to class and just not worry about it.