Happens to me all the time I have learned I am not going to pass out or die it just feels that way so next I just try and take deep breathes and relax it is very hard in the middle of a panic to do but with a little practice and recognizing what is happening to you you'll figure out what you need to do when the time comes.
well from what you say all test come back fine! GOOD! I can only give feedback on what you write about, You say, "I had several pvc's in a row--lasted maybe 5 seconds", sounds like you are really focusing in on your body,I do the same and have been working on accepting this is a normal body function, keep on with what I am doing.
BUT one big thing is you stated you DID NOT GO TO ER! great for you, really, I can not state enough HOW WE HAVE to give ourselves CREDIT for the good we do in helping ourselves! it takes time thats all I can say, time and work,