I installed the nvidia driver (installed the ubuntu-x-swat ones, updated them, got the updates for them, installed bumblebee. I restarted everytime I did those steps, so no, i don't simply need to 'restart X'. I tried to run things using bumblebee, but bumblebee was like "can't access GPU driver". So I ran nvidia-settings, it said the drivers weren't in use, so I ran "sudo nvidia-xconfig", then restarted.

Now, my login screen looks differently than it did before: it asks me if I want to load: "GNOME, GNOME - no effects, Cairo Dock - GNOME, System Default, or Ubuntu" when I log in,

but WORST OF ALL: i no longer have any kind of GNOME/unity GUI. There are no title bars above any windows, no close/minimize/maximize buttons. The unity bar is gone, and will not show up when I call it. And the top status bar is also no longer there.