First off - I applaud you on doing what you can to eat well. It's very difficult when you have a meal plan or limited ability to cook!
And this answer pertains to *anyone* with limited time and ability (or desire) to cook.
First, I would suggest that you try to make your snacks as full of whole foods as possible. Maybe you're always going to be having a dining hall dinner, but you can get snacks that are less processed - fruit, almonds, yogurts...all of these are going to be better than a protein bar or other processed snack.
Similarly, see if there are any meals in your day that you can cobble together a healthier meal. Maybe there's a salad bar available at lunch, or you can make oatmeal in your microwave. Look for those alternatives so you can limit the more processed foods when possible.
Lastly - let your voice be heard! Talk with the people in the dining hall or in the office cafeteria about what you'd like to see offered. If there's enough consumer demand, there will be changes!