lalala, many heart related problems I hve had. Four strees tests, with the cardiologist, treadmills, blood tests to determine if chemicles were present that would indicate heart attack. All normal...irritating to some extent, cause I still get pains shortness of breath, tingling tight right arm pain in my jaw and face on the right side (all classic symptoms of heart problems, and all irritating and scary.) Still no deffinitive answer as to why such real symptoms occur, besides anxiety and overactive thought processes.
Take heart in the fact that your age and seemingly good health would make you like a world record cardiac patient, of traditional heart problems beyond the bad valve or whole between chambers ETC.
Take haert that your tests have been normal. Take heart that you have good and bad days...somethong truly physically wrong with you, would mean you would justget worse not improve and then suddenly get worse.
Take heart, no matter how morbid, (this one helps me alot) that if in fact you had some sort of breathing heart problem, with as much time that hs passed since I first started to read your posts, something tragic would have deffinently happened already.
Our minds are so powerful, and can manifest aything into absolute reality and impending doom. Try to make it your friend. Try to cahallenge it to do other things which seem just as un-likely, but more fun. Try to lay down and concentrate how floaty you can actually make your self feel. Pretend you are actually floatimg over you bed.