Documents Folder missing MacOS High Sierra

Did you turn on iCloud Drive?

Turn off Desktop and Documents

1. From your Mac, choose Apple menu  > System Preferences. Click Apple ID, then click iCloud. On macOS Mojave or earlier, choose Apple menu  > System Preferences, then click iCloud.
2. Next to iCloud Drive, click Options.
3. Deselect Desktop & Documents Folders.
4. Click Done.

What happens when you turn off Desktop and Documents

When you turn off Desktop & Documents Folders, your files stay in iCloud Drive and a new Desktop and Documents folder is created on your Mac in the home folder. You can move files from iCloud Drive to your Mac as you need them, or select all of your files and drag them to the place you want to keep them.

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

Yes you have to drag them back...

What happens when you turn off Desktop and Documents

When you turn off Desktop & Documents Folders, your files stay in iCloud Drive and a new Desktop and Documents folder is created on your Mac in the home folder. You can move files from iCloud Drive to your Mac as you need them, or select all of your files and drag them to the place you want to keep them.

OK, do that, then in a Browser like Safari, go to...

icloud.com

Sig in& look for iCloud Drive, open that & Select All with CMD+a keys, drag to the new Documents folder in your Finder repeat for Desktop.

Whew!? :(

Can you see theDesktop folder in your Home folder?

Maybe make a new folder in your Home folder call Documents2 & try dragging the files there.

OK, good luck my friend. :)

:)