Anyone good at health please answer???:-/?

i was just wondering i am 24yearold...wen i had a echo cardiogram done and a heart monitor for 24hours i was 19 and everything came back fine they sed nothing was wrong with my heart because at that time i had bad chest pains so thats why i had that done..anyway..i was wondering is that to long 5years to not have it done againe?? i suffer from bad anxiety my heart always races alot now..wen i drink or anything and i get scared ppl tell me ohh be careful ur heart can stop but for that to happen i believe u have to have a heart problem dont you? and if i didnt would that test show something??? always this year at my age now i had a ekg done cat scane sonogram blood work xray..and nothing everything came back fine..so if all these test came back fine should i stop worrying?? it all in my head if i had a heart codistion it would of showed up??? and this prob just my anxiety getting to my had??? bc i hear of young ppl dieing from sca..sudden cardiac arrest so i wanna make sure:-0(