The only time I experience lag whenever I'm playing Toribash is when I move my mouse. Doesn't matter if I switch the graphics to maximum or to minimum, the same thing still happens (My computer can easily run Battlefield 3 on constant 60 FPS). It occurs in single player and multiplayer. Any help will be appreciated. Also, it's been running fine until I just logged on like 20 minutes ago.

Are your CPU drivers updated? What is your Gpu and CPU? Bf3 at constant 60 fps is very obscure because most low end cards can do so on low.