Thanks for the query.
A chronic gastric ulcer or a gastritis
is a possibility as your symptoms increase on eating food. You should probably get an upper Gastrointestinal endoscopy
A chronic H.Pylori may also be a cause.
A medical gastroenterologist would be able to help you with this.
Consider taking proton pump
inhibitors like Pantoprazole
. Eat bland diet, drink plenty of water.
Get well soon.