What Causes Recurring Severe Chest Pain With Breathlessness?

I have been told I have an elevated right hemidiaphragm, as well as a smaller than usual right lung. I have had breast cancer on the right side (27 years ago). I have also had reconstructive surgery, and I have asthma. I can t think of anything that might be helpful in knowing what this is from, or what it can mean to my health. I have also had some severe episodes of pain in my chest that last about 30 minutes. The pain makes it difficult to breath, or speak, and kind of mimics heart attack pain. My email is YYYY@YYYY