Just because something is "gluten-free" doesn't mean the ingredients it's made with are automatically going to be okay for your tummy. I guess it's hard to know which of the ingredients might not have suited you, and trying to find out which may be no fun.
Can you eat rice? Or buckwheat? (buckwheat is not wheat and is gluten free). The reason I ask is many gluten free breads are made with rice and/or buckwheat flour. If you can eat those, then that can't be what upset you
But there are some chemicals, additives, E numbers, oils, etc in gluten free products which might have upset you. Some commercial GF breads, cakes etc are full of quite nasty sounding things!
Online, if you have a scout round, you might find some good GF bread recipes with pure and simple wholesome ingredients. At least you know what goes in it if you bake it yourself.
But you'd need to know if any of the GF flours don't suit you.