Did you get checked for halicobectal bacteria? I think you have the infection called h-pylori. That is cured by simple erethromycne. I had that many years ago and I still get reflux every morning at 4am.
I do not like Antibiotics , but in this case I had to because I started bleeding inside. I have started taking mixture of ACV, juice from half a lemon, one spoon honey, half teaspoon of cyenne pepper and a few pinches of Sea Salt . I have done this for only three days. My mouth is not smelling and during the day I do not get reflux, but at 4am it does still happen.
I will keep you posted. I also would have your stomach checked for hiatal hernia.