I am sorry you are having such a hard time. We all understand how tough this is to deal with, day in and day out. Totally draining.
Something I am investigating lately (seems like there is always something new!) is the possibility of tonsil stones/sinus issues being part of the problem. Do you have tonsil stones/sinus problems? I know I do, and I've already been to an endo, ENT, GI doc, everything other thing you can imagine, but with no results thus far.
I am going to see a new ENT next week hopefully and see what he says. There has to be an answer, so we need to keep trying to figure it out. Don't worry - things will improve!!! :)