I have to just run away and think about something else

I know the feeling. I work in the food service for my dorm, and I get to SEE how unhealthy the food is. I don't know how your school runs their food program, but salads are a great deal at my school. You can get a large salad bowl with whatever fixings your heart desires, and I have never seen a bowl ring up at more than $4 (we sell by weight). If your friends insist on eating out at the local pizza joint, look into healthy options that they offer. I have found that several places have gluten-free crusts and are willing to make pizzas with less sauce and cheese while piling on the veggies. It will allow you to indulge once in awhile while not feeling extremely guilty. For the library, I have oddly found that I am less tempted to buy something that smells sugary if I have some sort of flavored water with me. I buy concentrated lemon juice from the grocery store and add a few drops to my water bottle before leaving. It gives it enough taste to be satisfying, and it has no negative affects on my daily totals.

In the end, it's all about making healthy choices. And I mean, we're college kids; we can't be healthy 24/7. The occasional slip isn't the end of the world, so don't over-stress about it. Just be sure that you're making the best food choices that you can. Good luck!