I won't kid you: The bump to 4.0 from 3.5 stinks.
I've been bumped three times, and each time it is hard to get used to the new level. Two things help.
One is working on fitness. Fortunately, this is free and can be a do-it-yourself project.
The other is working on your strokes and improving your technique and footwork. That may require instruction, which is not free.
Still, I think parking yourself at the low end of any NTRP level is no fun. So I keep working at my game.
-- Random Error Generator, Version 4.0
-- Master Moonballer