Oh my fucking god I deserve to be shot for my stupidity.
I spent an hour in absolute fear trying to figure out what was wrong with my PC - it would boot but the monitor wouldn't show anything.

I'd forgotten that I'd changed to monitor to show HDMI input - but I was using a HDMI-to-VGA converter so the monitor should have been set to VGA input :/

I had to switch machines in class. To continue working on my project, I needed to install 17 gb worth of Unity 2019 bullshit. Guess what? They removed the progress bar in the move to Unity Hub. Now I just get "Installing..." This seems minor, until I don't know if I'll be working in two minutes or two fucking days. What the fuck, Unity? Why would you remove a fucking progress bar?