Hi. Thanks for your query. Noted the history of you being a female of 63 years and gets hungry as soon as you take initial bites, mainly of potatoes. Gets bad pain right under breast, fells like the thing will explode, fells like burping would help and last for about 45 minutes. Taking Beano Ora or Pepcid helps if taken before. The most probable cause is severe esophagitis with inflammation increase with stomach acidity. This is the reason there is relief with Pepcid. I would advise you the following: Get an appointment with a Gastroenterologist. You need Upper GI endoscopy and esophageal manometry. Continue pepcid. Add on antacid. Soft bland diet. Small frequent feed. No stress or anxiety. This will help to tide over the crisis and the endoscopy will further guide for the proper cause and treatment.