Problem with GMod + Controller

I tried using a controller with GMod. It worked well for a few days, but it was fairly innacurate. I tried to go back to using the keyboard and mouse, but every time I tried to use the mouse I was unable to look around. I could look up and down but I couldn’t look round. When I tried to look round I just sidestepped instead. I set the controls to default and typed “exec undo360controller” into the console, but it didn’t do anything. Help me!

Uninstall and reinstall gmod. This happened to me.

Tried it. Does the same thing.