You can Control+Alt+F# to switch to other TTYs, aka non-gui consoles / terminals (depending on distro / init system). From there you can run tint2 or enable swap. One of the Control+Alt+F#'s should get you back the gui, used to be F7, now probably F1. Once on the non-gui variant, you can use Control+Alt+F#, but Alt+F# also works. From the gui you need all the keys.

$ export DISPLAY=:0; tint2 &

$ sudo dd if=/dev/zero of=/SWAP.swap bs=1M count=1000
$ sudo mkswap -v1 /SWAP.swap
$ sudo swapon /SWAP.swap

Creates a 1GB file, formats it for swap, and enables it. Once created, you only need to do that last one to enable it after boot, or add it to /etc/fstab and reboot to automate that process.

$ sudo swapon -s
$ free

To see that swap is there. It's ram as a FILE and a file that is a filesystem on a filesystem. Which is super slow compared to RAM, so you'll probably be aware of when you're using it. Beyond querying the statistics. But it should make things more stable if RAM is why it's having issues.

TBH, for issues like this, a fresh install can often prove the faster solution than trying to figure out what went wrong.

I did that and it said "export DISPLAY=:0; tint2 is not a command.

You would have to install it for it to work.

$ sudo apt-get install tint2

Is the kde - fc2, the version the came with fedora core 2 (like a decade ago or more)? What ever YUM method applies, if so. Although tint2 might not have existed way back then.

If you don't have to much customization done to KDE, you could try removing the $HOME/.kde stuff or $HOME/.config/kde stuff and restarting KDE / rebooting. Perhaps backup that first or rename them, so you can compare to what regenerates and ID what thing changed and what KDE called that thing. Or create a new user and have it start KDE to see if it's not an issue for a new user, then diff the configs. I would assume that there's some right mouse -> prefs or properties type option to toggle something like that (or will be someday).