Why Does So Many People Have Cardiac Neurosis And How To Deal With it?

I never understood this mental issue until i started experiencing it.I still don't understand it but want to get over it ,and fighting with it on a constant basis..Its my mind telling me there is something is wrong.I really don't have the symptoms of any heart disease or artery blockage been checked several times very throughly .I don't believe them .The reurance last about as long as it takes for me to be away five minutes and then I start worrying whether or not they missed something.How do you get over this?Its all in my mind..and others peoples minds.There must be someone out there that has had this and can give me some pointers.Its a miserable life living worrying about your heart..Anyone with constructive ideas please?