What Causes Pinching Pain In My Wrist?

Good morning Doctor. I'm a 49 y.o. female, 61.5" 120#, moderate exercise. My right wrist, just right of the bony part that sticks up (ulnar styloid process?) is soooooo tender to touch, and there's a pinching pain there if I sort of make a gentle fist and turn it so the finger knuckles face me. Ouch!