Have the same problem. I'd say if you still have the chance, then go get a tablet right now.
God forbit using a wrist rest for your mouse hand btw.
I'm left handed and still decided to switch to tablet 3 days ago, because even after almost 700h in this game my aim consistency is just beyond bad and mouse drift is a huge problem in this game aswell.
At first it felt like I had a stroke, because I couldn't even properly move the pen in my right hand, but now after 3 days I'm able to hit circles and am currently trying to find a comfortable grip and tablet area.
After that's done I can start practicing jumps and consistency should come naturally, unlike with mouse.
And depsite being nowhere near my mouse aim yet I already hit some jumps several times in a row that I wasn't able to hit with mouse before.
Maybe I just sucked hard with mouse, but tablet is defo the way to go if you want to make it far quick in this game.
I mean just look at Angelsim and especially Tuna who suddenly boosted his way through the ladder after switching to tablet.