Ubuntu 20.04 Server Suddenly has GUI and No Terminal

So I installed Ubuntu server 20.04 just fine, it was running without any GUI just fine.

I've been following this post to install TensorFlow with GPU support and when I tried to install NVIDIA Drivers 440 I ran the file and disabled the default Nouveau diver. I believe that everything installed correctly, but after rebooting my machine I seem to be stuck with a GUI that doesn't work. I can open the settings application, but that's it. Nothing else will work/run/start/load etc... I can't even open a terminal window of any kind to try to fix my problem. I don't even have the ability to navigate files using the GUI....

I believe that I have a identical issue to: Ubuntu 20.04 Server booting into a GUI but no solutions have been offered yet...

I'm fairly new to Linux and have no ideas on how to proceed from here. So any help would be greatly appreciated. I expect I'll just have to reinstall everything, but I don't know how to stop this from happening a second time.

Thanks for your time!

Solution 1:

This works up to at least Ubuntu 20.04: Log in SSH or CTRL-ALT-F3

sudo systemctl set-default multi-user.target
sudo shutdown -r now