I would not worry about guest coming, they can eat what you serve or go out! I do not bend over backwards for anyone, especially family. My FIL and his girlfriend just came and I served what we usually eat a meat plain baked, plain veggies, a few different types, salad and my out of my way item was Southern Corn bread which I make as a treat for my ds2. It was all GF as every evening meal I prepare is in my house. And there were no complaints -- if they were not satisfied they could get something at McD next to their hotel on their way back.

Don't hold off finding a solution to your food reactions, just do it and have other in your home deal.