I'm so sorry for your struggle. While I have not experienced tinnitus, my sister has. I happened to be reading the book "The Core Program" by physical therapist Peggy Brill. There is an excerise in her book that involves laying down, looking 'back' behind your head and sticking out your tongue. Bear with me, I know it sounds strange, but it was something about stretching the vagus nerve. Well, my sister tried it, and has had about 70% relief from her tinnitus! She can now function at work and go about her day in an almost normal way! She, too had been to several doctors, and had dental work to correct TMJ, but nothing gave relief like this stretch! I sincerely hope this helps you. Good luck.