I NEED SERIOUS HELP WITH CONTROLLER PROBLEMS

Somebody help me please. I've been playing the game all the last week on controller and for some reason now when I boot up the game, it doesn't register. I went into steam settings and enabled everything but it won't work still! The controller registers whenever I go to calibrate it but in game it just doesn't work. I've spent 4 hours trying every method in the book and nothing works. Can someone please give me some advice here? I really want to keep playing but M&K controls are just way too wonky for me to even wanna attempt it