Have you tried the alternative dental appliance? Lots of people don't seem to know about it, but I'm using one and it works:

https://news.ycombinator.com/item?id=22014204

I even heard on Joe Rogan that he has to use one. Not sure why more people don't know about it. I guess it depends on whether your doctor or dentist diagnoses it, but that shouldn't be the case. They should exchange more information!