So as I was sitting around watching YouTube, I decided to switch to a different video and as I clicked into fullscreen the screen went black. I clicked and as I did this a popped up. I didn't have time to read it because as soon as it came up it was gone. I turned the computer off and on, but it was still black. So I went and read a few things and it said to blindly log in and change the Project settings because my computer thought there was a second screen. I logged in and tried Win+P and I can see the menu on the right side, but it's still set to PC screen only. I tried the other settings and the screen stays black. I read a few other things aswell that told me I had to do something in control panel. But I can't, because I can't see anything. Send help please.