Hello, Welcome to the Community. We hope you are recovering well from surgery. With the biometrics unable to use the facial recognition, there should be an option to enter your PIN or password that was created when you added facial recognition.
Once the phone is unlocked, you can go into the Settings to change the method of unlocking your phone. This article provides steps to the different methods for screen locks. https://www.samsung.com/us/support/answer/ANS00078955/
