I'm sorry I can't think of a more descriptive title while being succinct.
I'm running Ubuntu 18.04 with a windows 10 host, and everything was working relatively well. I wanted to be able to have a shared clipboard, so I followed online directions and used the device menu to insert the guest additions disk, followed the prompts, and restarted the VM.
Upon returning, the window had reduced to a very small size and I was having a lot of graphical glitches (windows only loading element-by-element when the mouse is hovered over them), and it was running insanely slow. I had visual memory up to maximum, tried lots of different graphical settings, no luck. I wanted to uninstall the guest additions and see if it at least went back to how it was, but then I had issues with mounting the disk and it wasnt working as expected. In a nutshell, everything seemed to be broken.
After hours of being incredibly frustrated and messing around I eventually gave up completely and deleted the whole VM. However, I know that my computer at work is in the exact same state, and I'd like to know how to fix it so that I don't have to start from scratch and reinstall everything (only for it to probably break again when I try and get shared clipboard working). Does anybody have any ideas?