Hi sorry you are not feeling well. I also have had your symptoms. I had all of the tests also. I was diognost Functional Dyspepsia. I was given anti depression acid meds etc . Through this sight someone turned me on to a over the counter med called a FDguard. It is all natural made up of two main oils. Peppermint and one other it works wonders. Take two in the am and to before you go to sleep.you after a couple of days start processing food better and you can burp again. Look on line, they sell it on Amozon or CVS ,Walgreens. Good luck and keep a positive attitude. Mayo Clinic supports this treatment!