It's hard not to think the worst, but your heart has been wonderfully wired to keep running, and since you've been to the doctors and ER a few times, and they said all is well, try to think of them more as hiccups than, in your case, something serious.
If you had hiccups, you wouldn't presuppose that something was wrong with your lungs, you know them for what they are, an annoying thing that happens to your diaphragm. Same with these PVCs in your case. After I read that in an otherwise healthy heart, with no structural or rhythm issues other than PVCs, that an electrophysiologist said that you'd have to have more than 20,000/Day before they'd be concerned, I realized that the number I get is no where near that.
We're lucky, since we feel them, we went to the doctor and he/she said that ours were harmless, but many people get many thousands every day but are totally unaware that it's happening. I found a saying that exemplifies this concept:
"A saying from the area of Chinese medicine would be appropriate to mention here: "One disease, long life; no disease, short life." In other words, those who know what's wrong with them and take care of themselves accordingly will tend to live a lot longer than those who consider themselves perfectly happy and neglect their weakness. So, in that sense at least, a Weakness of some sort can do you a big favor, if you acknowledge that it's there."