desktop and documents gone

Here is the feature I was thinking about.

Add your Desktop and Documents files to iCloud Drive - Apple Support

If you had this feature enabled, and then "turn[ed] off Desktop and Documents", your files would still be in iCloud Drive – but you'd apparently have new, empty Desktop and Documents folders on your Mac. If you didn't know, or think, to check iCloud Drive, it would be as if all your documents had "disappeared."

This is why I'm wondering if this, or something similar, was the case for the OP.

Restart in Safe Mode followed by a normal Restart.

see > Use safe mode on your Mac - Apple Support

Also see > Organize your files in the Finder on Mac - Apple Support

Did you recently turn the feature to synchronize files in these area through iCloud either ON or OFF?

Restart in Safe Mode , prior to doing so please ensure the charging cable for the keyboard is plugged into the back of the Mac and the other end into the keyboard. Then restart normally and re-test.

Sounds like you enabled iCloud Drive.