Well, that's unfortunate. Assuming you are living in a dorm, you could try putting in for a trade with the head of the dorm if it was a very bad breakup. If it was, mention that you are worried im that living together will cause disruptions to the dorm, and/or that you are concerned for your physical and mental well being. Depending on the cause of the break up, you could also give it as a reason. If you rented an apartment together and have little wiggle room funds wise, or- heaven and hell forbid- signed a lease together... You're kind of stuck unless you can arrange to couch surf the entire semester.

Bring other girls to your room now.

Maybe try to work things out under the pretense that you don't want to have to share a room if she brings someone home, just as she wouldn't if you did.

OP, here! To clarify, my girlfriend and I are both girls, so that's why we're able to room together. We worked things out and got back together! We were going through a rough patch and the breakup was a heat of the moment thing and we both apologized. I did see all of your supportive comments before we got back together and they really helped me a lot, so thank you!

You can think of her as your friend or roommate and not as your ex

Not to be mean but you kind of deserved it. That's why you don't get a dorm together. My old college let you have opposite gender roommates and I had friends who did that. It never turns out well. Plus living with someone means you see a whole different side of them! I guess see if you can find someone to switch with you? The best thing to do would be to sit her down and tell her your worries for the next semester, and brain storm ways to fix it. Most colleges have things in place to help you in times like this as well. Also, sorry she dumped you op. Hang in there!