Track your food. Myfitnesspal.com works. We don't always eat what we think we eat. Get a food scale and be diligent in your tracking, and make sure you hit the goals. Here is good place to get goals: http://thefitcoach.wordpress.com/2012/07/29/584/, if you aren't willing to GOMAD. That's GOMAD, by the way, not LOMAD.
As for stress and studying, the gym is a sacred place where stress goes away.
Good luck!