Welcome to HCM.
I think it might be due to GERD or there might be some gastric erosions which is responsible for this pain.
You can make many lifestyle changes to help treat your symptoms. Avoid foods that cause problems for you. Avoid drugs such as aspirin
. Take acetaminophen
to relieve pain. Take your medicines with plenty of water.
You may use over-the-counter antacids after meals and at bedtime. Over the counter medication
like H2 blockers / proton pump
inhibitors are helpful.
I advice you to follow this approach and if it does not help i advice you to see physician for further help. i also advice you to go for ecg to rule out ant heart condition even though it does not seems to be related to heart.
Hope I have provided the information you needed.
Wish you good health. Take care.