As the others have stated you should see your doctor and get a drs note from him / her. Take that note to your school and they should definitely be able to accommodate you. I've always cooked my own food, so when I was in college I'd cook enough food for a few days to a week and then put it in tupperware. When I was ready to eat I simply heated it up and was ready to go .
Ugh. I remember when I was in college. What a hassle it was to eat gluten-free. I eat similar to a bodybuilders diet so what I would do is cooking a TON of food at once and just fill tupperware containers up. Then for a few days to a week all I would have to do is throw one in the microwave, or eat it cold. As the post above mentioned, rice cakes and pb is also a quick and good little snack when you're on the go.
Personally, since I've gone gluten-free I've grown about 3 inches total. You're still young. I went gluten-free at the age of 18 and those 3" came after 18. No need to worry yet.