The chances are that you are suffering from panic disorder. Your heart is fine. You are not having a stroke. This is panic disorder.
Panic disorder is an anxiety disorder that runs in families, and probably is genetic.
It manifests itself in brain chemistry, altered brain chemistry. All you have to do is alter brain chemistry, get it right again. This is done with medications. Probably only 10 percent of patients suffering from panic disorder are treated. People suffering from this illness just don't go to their physicians for help.