Nick, I understand wanting to lose the weight, but not eating is the number one way to gain! Or, hit a plateau. Eating the small frequent meals is not only good for diabetes, it speeds up metabolism for real, not just stressing your heart. Why not carry some Triscuits in a baggie for energy (whole wheat, not bad carbs), a piece of fruit, a packet of tuna (flavored ones are good), some lowfat cottage cheese in a thermal lunchbox with an ice pack, it's great with Triscuits! Lots of protein in it, too. Half a WHOLE wheat peanut butter sandwich (all natural peanut butter has no sugar added, no preservatives, just peanuts and salt).
These are things I usually snack on, yeah it can get boring, but it's nutritious, usable energy, and it helps with weight loss. All portable, too.
I think you have a great attitude about school, i know you'll do great! Just TAKE CARE OF YOURSELF!