I know what you mean about feeling cheated when you get accidentally glutened. I always think, "Darn, I could have had a real pizza or a croissant!" It's awful to get glutened by something stupid like paprika in potato salad or cross-contamination. However, I NEVER, EVER consider eating additional gluten once I've had an accidental glutening--the thought of getting even sicker always scares me.
BTW, yes, you might want to look for a new doctor--the one you has doesn't seem to understand celiac. For us, there is no "mostly gluten free." Good luck with the diet!