It sounds like you really have tried everything! I agree with the first reply. Maybe you can solve the problem during the day by giving him more attention. It's crazy, I know. I've been there! My boys are 2 years apart, and with a new baby, it seems like just taking care of her should be enough for one day! But if you think about it, you can find ways to give your son more attention.
One thing I did is while I was nursing the baby, I pulled up big brother right next to us, put my arm around him, and we read a book together. The baby was oblivious, so it was really more about me and big brother. I also told him many, many times, along with an extra hug, that no matter how big he gets, even when he's as tall as Daddy, he will always be my baby. It took several times before I got a shy smile out of him when I said that, and he didn't always even acknowledge it, but I know it sunk in because he remembers it to this day (2 years later).
I also tried to involve him in taking care of the baby, by bringing me diapers and the pacifier. We bought him a doll to take care of while I took care of the baby, but he really didn't get into any of that, but every little bit of attention helps.
It also helps to have one-on-one time with each of you after Daddy gets home. Daddy should be having one-on-one time with the baby, too, so spend about 10 minutes with one, then switch.
I hope some of that will help you get more sleep!