Hi Nina, and
I only know of one way to end the "yo yo" dieting cycle...making changes to your lifestyle. If you decide that you want to be healthier, you can make those changes. Weight loss will be a bonus, but you'll also be getting healthier!
My dorm room was SO small, you could barely turn around! But if you have the room, go for it! You might also check out whether there is a gym on your campus with free or reduced cost membership for students...if you HAVE the gym there, take advantage! I wish I had when I was in college.
Most of all, keep posting. We have quite a few college students on here, and you face your own challenges, but everything is easier if you support eachother.
Can't wait to hear more from you soon.