Hello,exercise avoidance is probably due to the shortness of breath/chest pain,I would suggest going to doctor and having a simple chest x-ray,it can rule out a lot of stuff,although the pain feels were the heart is,it could be the left lung as it is partially lies on top of the heart. If chest x-ray is fine,I would ask for inhaler for asthma as see if it helps.
Your asthma may have returned, or you may need to start excercising. My friend was having non stop heart pains, and the cause was that she had stopped excercising. But i would consult your doctor again, and make sure that it is not asthma.