Yeah, eating vegan while living in the dorms can be really difficult. Luckily, I had a group of vegan friends in my dorm freshman year, and we made meals together in the basement kitchen (among the cock roaches - heh). We would take food containers into the dining halls and stock up on staples for our meals (vegetables, etc.) and then bought cheap meat substitutes, etc., in bulk to spruce up our self-made meals. I realize that might not be an option for you, and if your school is like mine, you're probably required to be on a meal plan if you live on campus. Again, since I had a group of friends, we were able to meet with the head of the dining services to discuss getting better options in the halls. Unfortunately, this didn't come into effect until the following year, when we were all living off campus. I have another friend at a different school who actually met with the head of his campus' dining services to discuss getting out of the meal plan all together. He dressed in a suit, did his research to show how the meals on campus we're more expensive and not meeting his nutrition needs and argued the cafeterias were not open at times when he was available.
Peta offers some further advise.
Hope that helps. Good luck!