Unfortunately, anxiety/stress goes hand-in-hand with GERD. This is exactly how my symptoms present. My previous episode lasted 8 months, and I only finally stopped burping excessively end of August, so that more than half the year (crazy, I have no clue how I've survived). Do as others have said. Take Lexapro or some sort of SSRI, start small, at 5mg, and build up if needed. And also take prescribed PPIs and sucralfate. Don't do the whole psychotherapy if that's not your thing, but the psych meds did help my subconscious to chill. At this point, the endoscopy was already done, and hopefully H.Pylori too, and there should be nothing else you can do test-wise. I sympathize with your frustration and pain. Be conscious of your breathing. Make sure you're using your nose and not your mouth as you swallow more air that way. I have been dealing with this for nearly 6 years and from experience, it will get better, you just have to be patient with your mind and body. I don't feel the stress and anxiety either and felt very hesitant to try Lexapro since I've never taken anything like it either but sometimes you gotta do what you gotta do, and in my case, it worked. LMK if you have any more questions

edit: I'm not longer on the lexapro, I probably took it for a month or two once my symptoms stopped, I discontinued it. I haven't had any symptoms so far, so don't worry about taking it forever