My display wallpaper went black and i can't open any files

Hi, so i was using virtual box and i was trying to delete a folder of this virtual machine i created because clicking delete the machine file didn't delete it, i opened the virtual box program folder and i tried deleting it from there and that didn't work, so i opened virtual box and tried to find a way to delete it entirely from there.

I found this section in the program that looks like file explorer, i opened it and right clicked on the virtual machine folder and clicked remove.

I don't know what happened but my wallpaper went black, all my files are gone now and i can't open file explorer

Please help me if you know how to fix this