Dock not restarting after killall Dock

I recently needed to restart my dock in the terminal via killall Dock as I have done many times before. However, after doing so, the dock did not restart and my wallpaper is black:

This is very worrying as, despite multiple restarts and a host of other attempted solutions, I have been unable to resolve the issue. I have also looked in Activity Monitor for the Dock process but I have been shown nothing when searching for it:

This leads me to believe that the process has not restarted. My question is: How can I restart the Dock process to fix this issue?

Thank you in advance for any help, this is a very worrying issue for me as it has greatly limited the functionality of my Mac.

Kind regards, Rocco

P.S. this was the first time I tried killing the dock with that command in OSX Mojave which may be the cause of the problem. Maybe it is an issue with Mojave as I have never experienced this with any previous OSs

EDIT:

This was the exact, full command I ran before the problem occurred: sqlite3 /$HOME/Library/Application\ Support/Dock/desktoppicture.db "update data set value = '~/Desktop/wallpaper.png'" && killall Dock

tl;dr Run: killall 'System Preferences' > /dev/null 2>&1 && rm '~/Library/Application Support/Dock/desktoppicture.db' && killall Dock

For anyone who may experience this issue in the future, my issue was with the file located at ~/Library/Application Support/Dock/desktoppicture.db.

After doing some googling, I cam across the following two threads, here and here. Both of which suggest removing the desktoppicture.db with rm '~/Library/Application Support/Dock/desktoppicture.db' && killall Dock which solved the issue for me. You can read in more detail about the issue and proposed solution on the second of the two linked threads above