Angina Support Group
Angina pectoris is chest pain due to ischemia (a lack of blood and hence oxygen supply) to the heart muscle, generally due to obstruction or spasm of the coronary arteries (the heart's blood vessels). Coronary artery disease, the main cause of angina, is due to atherosclerosis of the cardiac arteries.
Just for clarification, stable angina is when you get chest pain during physical exertion. Unstable angina is when you get it at rest or during physical exertion.
Having enjoyed Unstable Angina for almost 10 years I can honestly say it doesn't sound like what you have going on. I also have GERD and can attest to the symptoms being much as you are describing...so it's simple, try some decent GERD medication and see what happens. I take pantoprazole daily and only have GERD now when I forget to take my pill.
Good luck