Well, there are a few tunes you can play with just one chord if you do happen to get stuck to the fretboard.

If it's a steel strung guitar you could try putting on nylon strings for the time being, or borrow a guitar that's already strung that way. They tend to be a little less painful. And lift the fingers a feaction in between strums (if that's how you play), rather than gripping it firm all the time, because that's what really makes it hurt.