Bhsockerunner,
Congratulations on your decision to quit smoking. It's a pretty destructive habit and quite expensive these days. I think the longer you review no smoking messages on this site and others, you will eventually see your friends and room mates in a different light. Nicotine addiction is one of the hardest to break away from. Sounds like you've made the break and your friends have not. They are current addicts and you are no longer a member of that group.
I know it may sound hard to do, but you're going to have to establish "boundaries" with the smokers you deal with so as to assure your quit. Such as "No Smoking in the Dorm Room", "Smoking Outside Only", etc.. You get the general idea. Considering roughly 75% of Americans no longer smoke, these ground rules should not be too much of a surprise. Besides, you met smoking friends when you smoked before, now make friends with some non-smokers. We're really not such a bad lot...
As for the stresses you feel from college, they probably won't go away. They do not go away after college either. You learn to manage them. Smoking will not make them easier to deal with. Rather it will add to your stress. When you quit smoking, you tend to calm down and mellow out a lot more too. So you have everything to gain by quiting.
Best of luck to you and please hang in there. By all means, do come back here often to chat with your new "No Smoking" pals.
Kevin__