Totally switch to a terminal first like you suggested and see if you can work your way from there. My suggestion goes after yours. Always try to fix the running system first.

It’s probably wise to check man pages and other introductory documentation for most system administration tasks. Even though they’re super low-level, they are in my opinion better to send than just pulling the power plug.

Even with a frozen system you can often still ensure data is written to inspect on the next boot. You may have a key labeled SysRq which likely needs an Alt modifier to trigger.

Alt+Shift+SysRq+s to sync data to disk. Alt+Shift+SysRq+u to unmount the disks. Alt+Shift+SysRq+b to reboot the system.

Execute them in that order.

This can help ensure the data about the mishap is written to disk so it can be inspected after the forced reboot. I also check the logs in /var/log but I suppose all of those are in journalctl too these days.

Oh you will suffer in the best way possible. You like the Slimbook now but in five years something will degrade, like the battery. You’ll think about getting a new one and you’ll look forward to it but nooo, you will not get a new one. You will look online and there will be parts available and you’ll repair it. Then you’ll need more disk space or ram so you’re hoping to get a new one but nooo, you will upgrade it. And then something will break and you finally see the part is not in stock so you mail them just in case but instead of an automated reply you’ll get a real response and they’ll get you the part you need. Sure, replacing a glued keyboard is a bit exciting but turns out a lot can be replaced. Not sure how old mine is but I like it, it just keeps running.