Left clicking doesn't work

just like it says in the Title, my left click dosent work. everything else is fine, but when i left click (to shoot, make an object, seleve weapon, etc) nothing happens.

WHAT DO I DO?!?!?!?!?!?!

try go into options, keyboard settings,and reset to default

that fixed it! thanks so much!

oh and rebind Z, resetting to default breaks the undo button, in console type

Bind Z undo