Apple Watch app keeps crashing on opening on my iphone 11

I received an Apple Watch 6 for Christmas. It seems to have paired mostly ok with my iPhone 11 (un-pairs itself occasionally when it's right next to my phone), but the Watch app on my phone crashes constantly immediately on opening and the Fitness app crashes when I try to sign in to the "Sharing" tab. Thanks to ios 14.3, I can't even completely delete the app to reinstall it. It's driving me crazy! Does anyone have any fixes for this that don't involve wiping everything from the phone and watch and starting over?