I have shortness of breath , I ben in the hospital twice and 2 year ago I have a heart attack , I get very tired, my joints hurt more than never I have Fibro for more than 10 years but after the heart attack I feel worse. the Dr did every test yo can think but he can find nothing with the heart , he said is the thyroid , I am Hypo, I can do almost nothing always tired and short of breath. what it can be