OP mentioned being told he was just worrying by a psychiatrist. They're used to seeing all sorts of psychosomatic issues caused by stress and anxiety. The old 'think horses not zebras' puts blinders on, especially when there's also claims that the US health system over-tests for things.

I told my gastro that I was on a very restricted diet. I had lost a ton of weight from not being able to swallow food and though it was related to Celiac or food allergies, and they really didn't listen to what I was saying. The psychologist told me that I was "so worried about gluten that I was starving myself", which was quite offensive, actually. I had been in phsyical pain every day for months and went from 180 lbs to 120 (at 5'10") until I found a liquid diet that worked for me and regained weight. I had no idea carbohydrates were an issue.