I always tell people on the forum that seeing a
psychiatrist could be one of the best things you can do for
your mental health, and also toward diagnosis. (I'm NOT saying you need a psychiatrist. Only that it will help with validation.)
Yet, still, even after seeing the psychiatrist, I linger on with NO test evidence of MS. I have signs and symptoms, but no positive MRI, LP, etc. So, I DO have moments of doubt, sometimes. That SUCKS, too.