This is just a speculation, but you should try to check on your aim too.
The fact that you have been playing relax–and having a bad accuracy on nomod means that even though you might be good at tapping at times, your aim/cursor could be leaving the circle too early before you could actually click it, because you got used to relax mod clicking it for you at the perfect time.
Also, to address your problem, try to play high-OD maps relative to your level. Just high-OD nomod maps, for accuracy's sake.
Edit: aim and tapping coordination, to be exact. Your aim is related to how your cursor moves, which has to go in sync with tapping.
kids, don't joke about rsi, it's not cool to have it, it doesn't inflate your e-peen, just makes you look retarded for being proud of it