I am new to this site! I searched this particular topic because I, too, have a TERRIBLE fear of heart issues. Heart disease runs in my family and has taken many loved ones' lives much too early. When I read about sudden cardiac death, I nearly fainted from the thought of it!
I have had an EKG and a stress test done with only "heart palpitations" to be found which my doctor reassured me is nothing to worry about. Like many of you, every single time my heart hurts now, I instantly panic. Let it be known that cardiac death is not common amongst the young. Yes, the media always share the stories of high school athletes who have passed from it. Many of those athletes had underlying SERIOUS heart conditions. So, if you're relatively health young adult who has had testing of any kind for your heart, rest assured you will be fine. I, too, still struggle with this, but when I do start to panic, I tell myself that I HAVE HAD some testing and that a problem WOULD HAVE been found. Immediately after these kinds of thoughts, I make sure to go outside and stay productive, so that I am not dwelling on the heart issue worry. Hope this helps!