Anything packaged or processed is usually a red-flag, unless it's labeled as gluten-free. Nature's Path sells some really good gluten-free corn flakes and other cereals. Also, there are yummy foods that you can get from corner stores and stuff if you're away from home. Smartfood popcorn, reeses peanut butter cups and nuts and dried fruit (read the label) are a tasty and safe choice.
Things will get better! Hang in there =)