Apple Watch
I can’t swipe up or down on my apple watch
If the Apple Watch has stopped responding,I suggest performing a force restart. Steps needed are found in the Apple Support article: Restart your Apple Watch - Apple Support
Which also contains instructions to force restart your Apple Watch,
i.e. press and hold both the side button and Digital Crown for at least 10 seconds, then release both buttons when you see the Apple logo.
If this doesn't fix your issue, try this
Unpair and erase your Apple Watch
after that get in touch with Apple Support for further assistance or tech service