long story short i've been having heart palpitations that have gotten quite bad and frightening the last few weeks. i can't tell if it's heart palpitations because of anxiety or something actually heart related but i do suffer from severe anxiety. it feels like a fluttering in the throat and chest, and sometimes a skipped beat with a heavy thump following it. 

i'm otherwise physically healthy, had an ecg when i was a kid to check for any heart problems, all clean, no family history of heart related stuff either, also had a stress test a year ago which came back normal. i even went to the er last week because of palpitations and they didn't find anything on the ecg, no heart rhythm disorders, no afib or inflammation or any other problems, also no heart murmurs. blood is fine too, just a bit low on iron. 

i'v been going crazy with worry that i might have an underlying heart condition that the ecg didn't show because the palpitations weren't caught on it... if i did have something dangerous or concerning (heart attack, arrhythmia, afib, etc), the ecg would have most probably shown it right? 

i really need some support right now