Hi ! From the history of gall bladder disease
and a hiatal hernia, it seems probable that your present pain under your right rib cage and right shoulder most likely is due to acute/chronic cholecysititis.
The daily abdominal discomfort, including belching and chest pain
radiating to the back could be both due to gall stone cholecystitis
, and hiatal hernia.
In my opinion you should consult a gastro enterological surgeon, who may advise you for a repeat ultrasound
to see the status of the hepato-biliary system, and also may do a repeat endoscopic examination.
Possibly you may have to undergo a laparoscopic cholecystectomy
first, after which you may become symptom free. If not the hital hernia has also to be dealt with.
For immediate purpose, you may also need to be hospitalised for intial conservative management of your problem and getting investigated throughly. Wishing you a fast recovery.