I had the same thing when I was initially withdrawing from Oxy. I had rapid heartbeat combined with a double hearbeat. This has happened on and off with me for years, The double heartbeat I mean. What happens is that my heart will give a rapid double beat and then continue on rapidly but normally. Rapid heartbeat is not a problem usually. Excitement. surprise, excercise etc. can all cause the rapid beat. Eventually, as mine did, it will begin to fade. It was about the twefth day of withdrawal that my heart started to respond normally. The important thing is finding a way to relax a little .
I know sometimes for withdrawls they use clonodine patches to help with heart rate. I have never had that problem. Stay on your medication for it. I am sure it is just part of your body adjusting.
that is awesome work!!!!!!!!!!!!