Very interesting. I don't have typical GERD presentation either. Mine is more so confined to my throat where it feels like a burning sensation. I also had that chest tightness you mentioned over the summer, but that symptom has gone down quite a bit to almost not at all. Oddly though, when I got scanned, everything looked a-okay. When I got scoped, it all came back normal and negative for anything and everything so the doctor recommended that I stop using the PPI in the absence of clinical pathology. I might try going back on Amitryptaline to see if it can help correct any sort of nerve misfiring between the brain and gut, however I don't meet the IBS criteria (no pain) although my stools have been insanely off. If you figure out anything that helps you that is natural, I'm all ears, and best of luck to you in your healing sooner rather than later.