This sounds a lot like what happened to me,
@Pappy . My Apple Watch kept showing low heart rates overnight, and even when I was just sitting and reading in the evenings. When it started dipping into the 30’s, I started worrying that it might just plain quit some night.
My doctor recommended a pacemaker, and that stopped the low heart rates, although it does not stop the a-fib.
Eventually the a-fib just got to where it was uncontrollable, (after two ablations) and they did an AV node block, which stops the heart from sending the electrical signals which cause the a-fib.
Now, the pacemaker totally controls my heart, and it does not go into afib at all, or into low heart rates.
The off-set is lower energy, but overall, I still have more energy than I did when my heart was in a-fib and i could barely walk back and forth in the house.
It took me a while to get strength built back up after the procedure, because the pacemaker has to tell the heart when to speed up and slow down; but now, I am still swimming over an hour most days, and walking in the house (back and forth like you do) to close all of my exercise rings and get my “Fireworks” at night.
If I can answer any questions, I am glad to share anything that might help you with this decision.