Win 8.1 Secondary Display saying Input Not supported?

I have a Lenovo Z580 laptop running Win 8.1. I have an old 14 or 15 inch acer monitor that I usually plug into my computer using a VGA cable. It is usually fine, resolution wise and everything. Last night, I tried connecting my computer to our 42 inch TV using a VGA cable, and it started out working fine. Then I tried to choose to only display to the TV, and that's when both screens just showed up black. I tried rebooting etc etc. And eventually gave up. Today though, when I connect to my regular monitor, it gives me a "resolution not supported" error and still doesn't display to either screen. For some reason I think it's stuck on displaying only to the secondary monitor but it can't because of resolution issues. I tried changing the resolution of my laptop to one supported by my monitor but that didn't help. I can't change any settings when I don't see the screen, so does anyone know how to fix this?