Empty Desktop

Were you using iCloud desktop and documents? Did you turn it on or turn it off? If so, your desktop contents have been moved (still on your computer) to your home folder.

This should help: https://support.apple.com/en-us/HT206985

Try a safe boot.

    Shutdown your machine.  Hold down the shift

key.  Poweron.  The boot up will take longer than normal

because the filesystem on the startup drive is being checked and

repaired as needed.   All about safe mode including what

features and apps safe boot leaves out. 

Safe boot uses a software driver instead

of using your machines video hardware.

http://support.apple.com/kb/ht1455

Your drive may be experiencing problems. Running safe boot will correct some drive problems.

R