You are having symptoms of congestive heart failure
(I am having the exact same symptoms). Talk to your doctor about this. He can order a Brain Natriuretic Peptide
(BNP) test which helps with this diagnosis. It is a blood test
despite what it sounds like. It is elevated with CHF. Ask your doctor to run the test if he hasn't already. You may also want to consider having a cardiologist take over your care for this. CHF is very serious, but can possibly be reversed with the right care. My own cardiologist is following my case closely.