All this summer I was and still am having weird problems like your self. I hope my thyroid nodule or thyroid levels are the culprit. I have been reading so much and can't beleive how many things the thyroid regulates.
My GP sent me to specialists and had them run scopes in all ends to try and figure out what was causing my GI and stomach/reflux problems. I was twitching all over and had hand tremors from time to time. Could not sleep. His diag was "its all in your head" and put me on Xanax. While this made me sleep great, I still had the other problems. I put myself on Prilosec OTC and that seems to have worked for the GI thing.
I know my thyroid levels have been considered hyper in the past I cant help but think that the thryoid could be the culprit.
I hate that the docs are not focusing on your thyroid more considering you have nodules and borderline levels.
The docs here seem to do the process of elimination route. You know something like, you have a sinus infection so they send you to get a colonoscopy to rule out colon cancer. Then they tell you, well, we know you dont have colon cancer. Next they might give you an MRI to rule out MS. Even though you went in for a sinus infection that they still have not treated.
Just keep calling them, maybe taking the pain in the A## approach might work.
Hope you get results soon.