I doubt that it will help, but try a Forced Restart.
https://support.apple.com/guide/iphone/force-restart-iphone-iph8903c3ee6/ios
More likely, the screen was on the verge of failing before the update, and the extra stress of the update process and restarting the phone pushed the screen over the edge.
Make an appointment at the Apple Store / Genius Bar or take the phone to an Authorized Apple Service Provider to get things fixed.
You can find a list of authorized shops in your area using this link:
https://locate.apple.com/