Here are some I started using when my wrist started to play up. They really helped, along with giving my hand a little rest for a few days.
Something I highly recommend is buying a wrist brace to sleep in. This stops you from smooshing your wrist in your sleep, or from tensing it into a fist. You can also wear it during the day when you're not drawing, to help you keep it still and rested. It's been a lifesaver for me. I've gone back to not experiencing much wrist pain at all, and I think a major part of that is bracing my wrist when I'm not drawing with it.