Angina is something that you would have great difficulty in overcoming. It causes pain and also acute breathlessness. I had this a lot and the pain you describe doesn't seem like it to me. Only speaking as a heart attack and heart surgery patient, not in a medical capacity.
I know it feels so scarey that when you have any type of stomach problems like acute indigestion, or infection that the worry is that it "might" be something to do with the heart.
I would take comfort in having the tests all come back as normal. Another thing, don't self medicate. This can cause more harm than good.