Hi my name is bibby about two weeks ago i read an article of an athlete collapsing from a cardiac arrest and?

know i cant get it out my head that it is going to happen to me so i gone to doctor done test like the ekg and he said eveything is perfect i dont smoke eat healthy and exercise and have no family history of heart poblems i am also a very nervouse person im 25 would appricate any help i cant sleep i am always thinking about this.