I don't meal prep as elaborately now that I am in maintenance. When there's a good sale, I'll buy items in bulk, portion them into sandwich bags, and then store them in my mini-fridge, and I sometimes plan my meals for the next day in the early morning or the night before. During weight loss, however, I meal prepped A LOT. I spent a good one or two hours on Sunday planning out my entire week, and then another hour putting things into bags to freeze and/or refrigerate. It was the best way for me to not "come home exhausted or just grab something from campus instead," as you've written. I also invested in a rice cooker. It has a timer, so I just put whatever I want in there in the morning and set it to be ready by the time I come home. Yes. It was a lot of work, and I had to multi-task with my studies (i.e. listening to audio lectures as I shopped/cooked), but I made time for it.
If all else fails, just learn to incorporate campus food into your calorie goal. Google is your best friend to find calorie and other nutritional information on restaurant or fast food. I recommend these MFP threads for a little extra help:
http://community.myfitnesspal.com/en/discussion/10213155/a-guide-to-going-out-to-eat/p1
http://community.myfitnesspal.com/en/discussion/10399642/meal-prep-ideas

I find making a big meal or two on the weekends (that intentionally makes a lot of left overs) helpful. That way I have healthy yummy food just waiting for me when I get home after a long day. I also plan out what I am going to bring to campus for snacks and lunches when I go grocery shopping. I'm usually too lazy to portion out everything out after shopping, but just having in mind " Monday lunch - left overs from Saturday evening + apple for snack, Tuesday lunch = sandwich + grapes + carrot sticks, bring walnuts for snack, etc" allows me to throw them together morning of.

I noticed my weight loss slowed and even stalled when I stopped doing this around mid-terms and just ate whatever including a lot of food from campus. Even though it takes time energy to put things together, I usually feel better (more energetic) if I'm eating my own food during the term.