i tried to get kde plasma on my fedora, when i booted it up there was just a black screen. i couldn’t type any commands either, it was toast
thankfully i’ve got windows dual booted because i’m a filthy 
who uses it for vr games. unfortunately windows doesn’t let me see my linux drive’s files so all of my personal files are unrecoverable.
thankfully i think the most i had on my computer was my music (yt-dlp is so easy i can get it all back in 30 minutes tops) and a few files from some project i was working on, sucks but not worth spending hours troubleshooting. oh well.
on the bright side, i’m RETVRN-ing to my old reliable, linux mint with xfce. i’ll miss hot corner and the other niceties that gnome has but xfce will be a bit more comfortable for me.
Just make a bootable usb key with a live distro all your files should be easily accessible.
I second that. Always have a bootable disk ready (or even better a bootable image on your machine) so you can recover from any issues in a snap. Over the course of 20 years using Linux I can only remember two blackscreens. Unlike other OS, these situations don’t happen randomly but mostly when the user mess up with the system (like in your case) and that’s great opportunities to learn a lot about your system because that’s when you really need to understand how it works.