Thank heaven you are okay, Beth. In 1955, before heart attack symptoms were common knowledge and before the ability to search anything in an instant, my 39-year-old mother thought she had severe heartburn and indigestion for three days. She died of a massive heart attack just like your father.
Try not to worry about the hospital bill or the news you received in the mail. I know that's difficult, but constant anxiety can weaken your heart and cause future problems. Be gentle with yourself. [Hugs]