I pressed a button by accident, but I don't know which one, and suddenly my mouse scroll wheel zoomed ridiculously far with each turn. I went to render window properties to change zoom speed and clicked apply after quartering it, and it didn't change the speed at all, but what did happen was things dissapeared (not suddenly, inch by inch like pulling an invisibility sheet over it) gradually as I move the view around. I'm not sure exactly the pattern it's happening in, it seems to get rid of more of the image at a lower angle, and it sort of seems like it's doing it based on what is closest, but it doesn't do anything when I zoom in. Please help.

Oh, I think the problem with zooming might be caused by something I realised now, it's showing the image with no perspective, no illusion of depth. How do I fix this?

You must have hit it 0 (zero) by mistake. Hit it again to turn off orthographical mode.

Thanks, that seems to have solved it. I'm having another problem though... my ambient lighting settings are not showing up correctly in game. I originally had them set high and it was way too bright for what I wanted so I lowered them and they appear lower in the CK but not in-game, and this is after loading a save I made before I went inside the interior for the first time so it shouldn't be a problem that way. I do have a currently unfixable bug for shadows on my game (weird flickering and dissapearing shadows, have not found a solution that works for my PC) but it usually doesn't just make everything bright, so I don't THINK it's that.