You may be able to get the dining hall staff to help you out. Many schools, colleges, and universities now offer vegetarian and vegan options, or will if you talk to the staff. They may not know you need vegan options! Just ask really nicely. And keep asking. And ask the person's boss, and their boss.
Find out if the beans, veggie patties, breads, pasta and rice they serve are vegan, and if they are not, ask them to change. You never know until you ask! Ask them to offer vegan steamed or sauteed vegetable options. Be polite, but be persistent. Is there a dining hall that offers special meals for those with food restrictions that are religion-based? (For example, offering Kosher or Halal options.) Even though those food restrictions apply primarily to how animal products are prepared, it is far more likely you'll find vegan options there because of rules about combining meat and dairy. When I was in college, there was one dining hall that served food that was exclusively Kosher and vegetarian. There were always vegan options there in addition to the ovo-lacto options. In addition, there was always something to eat at the other dining halls - pasta, veggies, salad bar, something. And the salad bar always included beans and tofu. If yours doesn't, request it, and ask your friends to request it too!
Band together with other vegetarian and vegan students to request more hot vegan options. The food service staff may not realize that there are vegans on campus. And they may not realize that the salad bar isn't enough - you need hot food too! It is their job to make sure you are well fed! Make a petition. Enlist the help of alumni, parents, faculty and staff who are vegetarian and vegan. You can't be alone - there must be lots more vegans at your school!
Back to the dorm. You're getting tired of PB&J and salad. Got it. Have you tried mashing a banana into nut butter? It is heaven. Try it instead of your PB&J. Try it straight up, or on rice cakes for variety. Try apple butter. It doesn't usually contain dairy or sugar - just apples and apple cider. So good!
Have you tried different, nontraditional salads? Make a dressing of tahini and lemon. Toss with shredded cabbage and carrots - you can find it labeled as cole slaw mix. Or start with your basic salad, and add some drained, rinsed canned beans, or some sunflower seeds, red grapes, raisins, baby spinach, orange. Make a sophisticated dressing with dijon mustard, olive oil, orange juice, balsamic vinegar, and salt and pepper to taste. (You can find fairly inexpensive balsamico if you hunt. And the OJ helps to extend it so you don't need as much!) Try cilantro with lime juice for variety. Making your own dressing is easy and will save you a lot of money. Keep extras in an old dressing bottle or nut butter jar in the fridge.
Try putting your salad in a pita for a refreshing, different sandwich. Add sprouts for crunch and nutrition.
Do you have a way to heat water, or a place to obtain hot water? Do you have a friend with an electric tea kettle or coffee maker? Many schools will have a coffee machine with a hot water spigot somewhere, either in the cafeteria or elsewhere, like a staff lounge. Use some hot water to make some ramen noodles and toss them with your favorite nut butter and some hot sauce. Top with sesame seeds. If your dining hall offers vegan spaghetti, peanut butter, hot pepper flakes (maybe by the pizza station) and soy sauce, you can even assemble your noodles right there in the dining hall, for no extra expense! Improvisation is key!
A rice cooker is invaluable - maybe you and your floormates can share the expense of one. It will save you a lot of money and frustration in the long run! Here's a link for a super cheap one
Prices start at $6 on on eBay for that search; $12.99 in actual stores.
You can use your rice cooker to cook brown rice, oats, millet, buckwheat, or pretty much any whole grain, and also to steam veggies. Buy your grains in bulk, and check the price per pound on the bulk and on the packaged versions. Whole grains should be affordable! A rice cooker is awesome and more than pays for itself! You will save so much money that you might have spent on prepared foods. I use mine all the time, and definitely not just for rice.
Here's a link for some easy and cheap rice cooker recipes:
Most of the recipes there are vegan or easily veganizable (just use oil anywhere you see a different fat, veggie broth or water for other broths, and coconut milk or your favorite non-dairy milk anywhere you see the other kind. And skip the one recipe that actually contains chicken.)