Glad you are staying in touch with the doctors and following the advice etc.
When I was having a hard time with heart symptoms I did actually take time off work in the end, a day or two, I told my doctor I'm not going while it keeps happening. He seemed concerned that I wasn't going to work, but in fact, I went to bed, gave up, didn't know what else to do, and all my symptoms went away. I get them from time to time but that episode went away and I think sometimes you just have to rest if everything else doesn't work. Sometimes we just need rest and there isn't anything else wrong.
Only other thing, are you staying hydrated? Would it be worth trying some magnesium supplements? (often advised by Dr Sanjay Gupta, York Cardiology).
I wish you well :-)