i'm not in dschools, but i know a thing or two about living in my office at the school. i LOVE alfredo pasta, so usually every couple of weeksor so, i'll go buy a 2-4 lb bag of bone/skinless chicken, a box of whole grain pasta, a jar of alfredo sauce and a 2 lb bag of frozen shrimp.
cook the whole box of pasta, grill all the chicken (season if you wish), and just throw in as much shrimp as you want. all that with the sauce, you now have a 5-6 solid meals for the week at a fraction of the price you pay at a nice restaraunt. and if you want, just steam some broccoli and throw that in there two, or eat it on the side.
i also make a lot of sandwhiches with bagels instead of normal bread. you get a few more extra calories (good ones) to get you through the day and i feel like they fill me up better and for longer periods of time.
PM me if you want some more ideas. i'm not a nutrition expert, but i was a personal trainer for a couple years and am ACSM (american college of sports medicine) and ACE (american council on exercise) certified 😀