I spent a whole half term working overtime after a colleague fell off a roof which didn't help. My work involves a lot of jarring because I do the preparation which involves attacking carpets with a broom, as well as holding my wrist rigid for scrubbing walls and tables, which is what the nurse at Wycombe minor injuries unit said was the cause of the problem. I only got 4 days off over xmas so I was definitely overworked!
I suspected as much! Unfortunately i know how much it can hurt, above suggested was a powerball which works very well as well as i found improving my grip strength helped.
A way to do this was hold a dumbell in you hand with your forarm resting on your thigh, sitting down of course! And as you would do bicep curls do "wrist curls" let the dumbell fall to the floor and extend your fingers so your holding the dumbell with a limp wrist just in your finger tips, and curl back up towards you.

Start of small as always, light weight small reps and about 3/4 sets and work up slowly towards 10-12 reps, 5 sets, medium weight. And remember to stretch out before and after and ice and elevate for a small period after. This should hopefully help not only your pain but should put some more revs on those googlys!