There are a couple of mouse cheatcodes, but they don't seem to apply to your situation.
In your place I would do <alt>+<ctrl>+<F2> that key combination should put you into a shell.
Then type 'dpkg-reconfigure xserver-xfree86" <enter> You should then get a chance to
reconfigure your entire XF86 configuration. You might have to run through the program a few times to get it set up right. Hope that helps.