Can you enter the Grub Menu from Boot.
Then select Advanced Options for Zorin
First thing I would try is booting into the previous Working Kernel as a test. If that works, then that should be all you need. You can then set that kernel as your default boot.
If not, From Advanced Options for Zorin, select Zorin on 5.15...(Recovery) and enter the Recovery menu.
Arrow key down to enable networking.
Once enabled, back up to the Recovery Menu and arrow key down to Root - drop to prompt
Bad the enter key...
Run
sudo dpkg --configure -a
sudo apt update && sudo apt upgrade
Read the terminal output. Make sure no errors. If none - test a normal boot.