I visited my GP, 2 wrist specialists, and physical therapist to help deal with it. I had multiple x rays and an MRI done. Steroid injection done. All without relief. My last wrist specialist even recommended I just learn to accept it and don't try to extend my wrist too much.
I decided to ask Gemini, and literally the first thing it suggested was maybe the way I was using the mouse was inflaming an extensor muscle, and it suggested changing my mouse and a stretch/massage.
And you know what, the next day I had no wrist pain for the first day in a year. And it's been that way for about 3 weeks now, so I'm pretty hopeful it isn't short term