Ok, so I spent the better part of the night messin’ around with the XFCE4 desktop, because I somehow had erroneously made my entire background disappear, as well as the main system menu which appears when you right-click the mouse.

After scouring the web all night, I came across this post.

Basically, in short (Nautilus is to blame):

“I guess that’s because xfdesktop is not running.
Kill all instance of Nautilus, then launch xfdesktop. When you’re fine,
log out, and log back in. If the session manager is running (this may
cause Nautilus to launch every time you log in) it should restore
everything as you expect…”

Read the full thread.

It’s also supposed to be answered somewhere in this FAQ, but I found the paragraph above fixed the issue for me!