Hello! The Problem With My Issue Is That I Do

Hello! The problem with my issue is that I do not know when it occurred or if it's always been there. Many years ago I was at the doctors and she noticed one of my eyes bulges out just slightly. She suggest I may have a thyroid issue. So went and was tested and no luck there! Years went by and I didn't think about it. Someone eventually brought to the light to me it could be a tumor. Naturally I panicked, had a CT scan, MRI, AND blood tests, and was seen by an eye specialist given multiple tests. No luck. The issue I have is that it feels different than my other eye especially when my allergies flare up, which I suffer from immensely. No pain behind the eye either. I just feel so distressed with no answer. I barely sleep at night thinking it's something sinister they failed to find. Please help.