Thank you for your query.
You most definitely sound like you are having gastritis
or acidity, as the pain responds to antacids.
The swelling you are described could be mild fullness or distension after meals.
Also, it could be musculoskeletal pain
where you have pulled some muscle, but then it would not last for 5 years.
Also, sometimes, breast lesions can cause such pain.
You need to see your doctor, have a detailed evaluation.
You might require endoscopy
to diagnose the cause of the pain.
Do not take it lightly, as you have had it now for 5 years.