I have also had BMS for years. After finally being correctly diagnosed I found a great oral medicine specialist, whom I now see regularly. I now have two tools that I use that do a pretty darn good job of managing my symptoms. 1) Doxepin Hydrochloride oral solution, USP (concentrate) equivalent to 10 mg/ml. of Doxepin – swish and spit, 3-4 times daily as needed. Works as a topical anesthetic. 2) A third to a half of a piece of sugar-free gum ( I use Trident Tropical Twist; I tried, and don’t recommend, anything “minty”) – “parked” at various places in the mouth. This apparently serves as a “distractor,” interrupting the faulty nerve signals. I also have TMD, so chewing gum is generally discouraged. However, just chewing to soften for a minute or so, then, I just periodically move the small portion of gum (about the size of a blueberry) around in my mouth, positioning wherever it feels comfortable, this helps a lot.
Anyway, hope that passing on these tips might help someone else.