I have TMD due to head trauma which pulled/knocked my jaw off it's hinges. I had to do a year's worth of exercises with a PT before the oral surgeon would do the surgery. Also began with a pain management psychologist,as learning to manage pain increases the good results from surgery.

I understand the horrendous pain! You do need physical therapy to stretch those muscles (including the ones inside the back of your mouth.) Wearing a fitted jaw "splint" at night especially will help your muscles be able to relax, and probably allow your jaw to go back into place on it's own. You do need a DMD or oral surgeon to do this properly. I had the best in the State do my stuff, but now have a DMD keep up with what I might need. (I had my back teeth built up so they meet properly and I don't need the splints any more.)

Neck and shoulder exercises, along with jaw stretches will reduce the pain of TMD (formerly called TMJD... "tmj" means temporo mandibular joint, of which everyone has 2! )

Take care of it as soon as you can, as it will affect the rest of your life, and your body. TC!