I just thought of another thing I used to do. I would wear a mouth guard while I slept. There was a time when I would wake up and my jaw and head would hurt really badly. I bought a guard at the pharmacy and it really helped!! I think I had added stress in my life that triggered it. I guess it reduced the grinding I was doing. Just a thought.
Definitely be persistent with the doc! Sometimes that is all we can do!! Good luck!!