All great advice so far!
Did you know that our children, even babies pick up on our emotional distress and our stress? This could also be what is causing him to fuss. Yes, I may be new agey but I also am majoring in Education and just finished a child development class, so its fresh in my mind. lol. Try to be as calm as possible when holding your son, no matter how much stress you are under from lack of sleep. Projecting a sence of calm may help him feel better.
And right on for massaging gums! That really helped my daughter.
The biggest thing about teething is time. It will run its course and all you can do is ride it out if nothing seems to work. Just like many moments in our children's early growth stages, they are gone so fast or they take so long to get through!