You don't mention if you Dr. is an MD or a DO. I, as others on the boards have found, Osteopaths tend to treat symptoms, not just lab # and they often seem to listen to you more.
Have you ever had anything other than thyroid checked? Perhaps your Dr. would run antibody tests that would tell more of the story. I am discovering that many people have autoimmune things going on and it is never found until critical conditions are reached. Many of these autoimmune things have the same symptoms of thyroid problems and it is difficult to tell the difference unless one looks.
Good luck and I hope you feel better soon. May God Bless You