Life kinds of stinks for a while when you go gluten free. The following are some things that my family eats and packs in their lunches that aren't sandwiches and don't involve GF bread. Many are Gluten Free, Dairy Free, Paleo, and SCD/GAPS legal.
mash up a cold potato and fill it with filling of choice (meatballs, tuna fish, lunch meat, broccoli and cheese?), close it up and eat it like a sandwich.
Kebab: because pretty much anything you put on a stick is cool
sausage + pineapple kebabs
Tater tot + meatball kebab (store bought meatballs almost always have wheat in them)
omelets cut up and put on kebab with cherry tomato and salami
cherry tomato, basil, mozzarella kebab
If it's firm enough to make it onto a stick you can skewer it. I like to do a protein and a carb but a fruit skewer or all meat skewer would work as well.
Bake Ahead of Time:
Pumpkin pie clautofis This packs well in lunches and is best served cold. Gluten Free, Dairy Free, Paleo, and SCD/GAPS legal.
Paleo Breakfast bread: super easy to pack in a lunchbox and tastes good at any temp (add tiny chocolate chips if you feel like pickier eaters wouldn't want to try it, I do think the recipe needs more sweetness so I add honey and more cinnamon) Gluten Free, Dairy Free, Paleo, and SCD/GAPS legal.
Almond Soda Bread: I use half almond meal and half cashew meal. Gluten Free, Dairy Free, Paleo, and SCD/GAPS legal.
Socca: This stuff is best hot and crisp from the oven but makes a super easy, super cheap cracker when baked up thin. Gluten Free, Dairy Free, Paleo, and SCD/GAPS legal.
SCD/GAPS, Paleo, totally delicious, my kids hate sweet potato but love this
you could also use hash browns if you aren't interested in sweet potato
tortilla chips and guacamole or hummus or bean dip
cabbage cups instead of tortillas or sandwich bread, you can fill these things with tuna salad, chicken salad, diced chicken, pretty much anything you would put on a sandwich except PB and J (yuck).
corn tortilla and anything you can put in a sandwich. These roll best if you heat them first.
We've also tried apple sandwiches by coring and apple and cutting it up into bagel like slices. It's just easier to cut up an apple the old fashioned way and eat it with peanut butter.