Close any open terminal emulators that are holding the editor in place. Your changes won't be saved unless you take action to save them.
You can remove the /etc/default/.grub.swp file if you want to.
To boot into the Previous kernel, you can do so directly from the grub menu.
Reboot and tap esc if using EFI boot or hold Left Shift Key of using MBR boot.
Choose Advanced Options for Zorin and then select an entry that lists Zorin on 5.15.0-76 or earlier kernel to boot into. Do not choose the one with (Recovery).
Booting into it - you can then test if it resolves your issue. If it does resolve your issue, you can either lock yourself into that kernel or you can remove the latest kernel using Synaptic Package Manager.