59 to 63 bpm is quite low (although not alarmingly so). Around 80 bpm is considered 'normal' (if there is such a thing), with quite a bit of variation not being unusual. (My own resting heart rate is usually in the low 80s but it's been anywhere between 77 and 97 over the past few weeks).
Fitness trainers generally regard an athlete's resting heart rate as largely irrelevant anyway, regarding the time it takes for the rate to fall back to that level after exercise as a far better indication of fitness.
So the raw figures you've been seeing don't, in themselves, seem to be a cause for concern. The arrhythmia clearly needs investigating though. While you're waiting for your GP appointment, here's some general info on the subject:
https://www.nhs.uk/conditions/arrhythmia/