I'm not a health professional so take my comments as a patient, not a healer, and I could be way off base.
I'd strongly suggest you contact a Gastrointerologist and have an endoscopy as a start. Also, there is a nasty little procedure done by ENT's where they drop scopes down your nose and ask you to sing, say the vowel song.
I had it done as my voice simply went from a nice deep base to sounding like Kim Carnes. I can't sing a lick, but used to have a great speaking voice. Turns out I had silent acid reflux caused by damage to my LES valve, long story. Once that was fixed, my voice stabilized. It isn't an easy answer, but sure sounds like you should actively chase an answer. Also, check with your dental hygienist to see if enamel is eroding. Keep us informed.
From my experience, voice changes needs to be checked out by an ENT and there further tests can be ordered if it indicates GERD damage, etc.
Please keep us informed.
All the best,
Perhaps you can use Chris Kresser's approach to reflux. Basically it's about gettig more stomach acid so the esophageal sphincter closes: Cutting away carbs and eating HCL pills. I am having some sucess with it although using it for another purpose. Google his Gerd and heartburn article, give it two weeks and check to see if you feel better. And don't forget to write about any positive results in here ;-).
Here is his article. Set a few things straight for me:
There are so many causes for acid reflex damage, there are no real internet cures. For example, I had a bowel obstruction that caused some very violent vomiting, which literally destroyed my LES valve, allowing acid to enter my stomach. In a very short period of time, the enamel of my teeth started dissolving, think a couple of weeks, and my vocal chords simply burned up. Surgery relieved the situation (Nissen Fundoplication), I had my teeth re-enameled at a very high cost, and I can talk again. I guess people that toss their dinner on purpose get this, that certainly wasn't my problem.
Beware of internet cures and nostrums, see a doctor, get the tests, and deal with your issues at a profressional level is my suggestion. Keep us informed.