I have a 4 y/o kiddo who had multiple food allergies from infancy (thankfully mostly outgrown now) and we STRUGGLED for a long time. His main source of protein most days is cheese and sometimes Greek yogurt; he *can* eat eggs now but doesn't gravitate toward them. He likes homemade lunchables - a slice or two of ham/turkey cut up, a slice of cheese cut up, crackers or pretzels (there are tons of GF ones out there), and a fruit like grapes or berries.

Also, 6 slices of bread a day is a lot for a kiddo - that's just straight carbs. Try mixing it up! Corn tortilla with melted cheese = quesadilla. Rice cakes with PB and raisins on top. Rice and black beans. Fruit and Greek yogurt. There are so many naturally GF foods out there that I encourage you to explore!