I feel better without challah too, which is why I do not eat it. But I don’t know if that is a solution.
How about making mini-oat challot?
Is it the wheat or gluten? Or grains in general and yeast?
I don’t know how many people you share Shabbos meals with, so that may be a factor in how to manage challot on Shabbos.
Is there a rule that you must consume a certain amount of challah on Shabbos?