Nice progress so far. I really just started the same as you around 2 years ago with 30wpm, but I'd just keep practicing until I could reach a decent speed. From my experience, if you really want to step up the speed you first need complete confidence of blind typing (i.e. don't look at the keys while typing), second you need to repeat certain quotes that are kind of easy for you but are long as much as even memorising one so that you get used to typing at those speeds along with continual typing in all quotes (dw about the ones with too much punctuation and grammar but they are also good practice.)

When my fingers hurt after too much time on the keyboard, I...
Keep typing, there is no stopping..