Hi
Apple advises that you should not continue using a damaged Apple Watch. Apple Watch is not user-serviceable and Apple does not offer a screen repair or replacement service.
If the issue is not covered under warranty or other Apple policy, then your Apple Watch may instead be eligible for replacement via chargeable, out-of-warranty service - or via AppleCare+, if previously purchased.
Prices vary by model and region. Apple's out-of-warranty repair prices in the US, for example, are detailed here:
Apple Watch Service Pricing - Apple Support
Contact Apple Support (mail-in service may be available, if required), make a Genius Bar reservation or visit an Apple Authorised Service Provider to arrange for your Apple Watch to be inspected and to establish your available service options:
- US: Apple Watch Service Answer Center - Apple Support
- Elsewhere: Select your country for Apple Watch service and repair information
(Note that you are not talking to Apple here - this is a user-based technical support community).