J.C.
This is much easier said than done, but the one thing that always worked for me w/my daughter was to have a serious heart to heart. Sometimes I could get her to explain why she was having a hard time sleeping in her bed (or whatever the issue at the time would be) and just talking about things that might help and treating them like another person, and not a baby might help (not to say that you're treating him like a baby:) I think it's going to depend on the child, and how he best communicates, or who he feels most comfortable talking to, but it could be something as simple as a change in bedding, or an added special pillow, or maybe there is something in his room that frightens him in the dark. Hopefully it starts to get easier soon, you guys sound like you need your rest!