Reta, cheap tuna, and dining hall survival

I’m a broke student living off dining hall food, so my version of a reta update is less wellness influencer, more “will this cottage cheese cup survive my backpack.” Twelve weeks-ish in, down about 19 lbs. The weird part: I’m not white-knuckling it. I just eat a lot of tuna packets, microwave eggs, and those sad little yogurt cups. Dining hall chicken is still dry enough to register as a study tool, but I’m full after half a plate instead of going back for round three. My budget also noticed: protein is now canned chicken, lentils, and whatever eggs are on sale. Side effects have been mostly boring, which I’ll take. I still get snacky at night, but it’s popcorn or tea, not a full second dinner. For people also doing this on dorm food: what’s your cheaest protein that doesn’t feel like punishment?