I don't know much at all about Compasses, but since no one has given you any type of answer I'll at least give you a guess. Are you sure you checked ALL the fuses? Newer vehicles have several fuse panels, and the one under the hood is often overlooked.
Do you still have tail lights? If you have no lights working in the rear whatsoever, you might have disturbed a ground wire while you were messing with the hitch wiring. Maybe one of the pins inside a plug got pushed back into the plug and is not contacting its mate.
That's all I've got. Hopefully someone with a little more vehicle specific knowledge will find you.
