My boyfriend has been depressed for almost a year..our relationship is suffering dont know what to do?

my boyfriend was married to a woman who brought 2 small children into the relationship..the youngest child was very young when they became a couple..this child was raised as my boyfriends daughter. In Fall of 2009 His now ex-wife began a new relationship behind his back..leading to a divorce which became final in spring 2010. His ex-wife allowed him to have visitation two week days each week and every other weekend...suddenly in Aug. of last year she stopped these visits ( because we refused to feed the child leftovers from their home..they tasted spoiled!) In KY step parents have no legal rights, she has no contact with her birth-father..he was the only father she had ever known. Well this loss ( he has not seen nor talked to her since he left for work that awful day) sent him into a constant depression and it has not lifted in all that time. At his request I moved in back in September..but nothing has been the same since that Aug. day. I have asked him to please get help, I listen to him when he talks about stuff, I hold him when he Cries, and I try to give him time for himself. Not that Sex is the most important thing in the world, but that went from about everyday (him initiating) to once a month (me initiating)..he isn't cheating their is no time for that we work at the same place, and have similar hours..it is just his depression. He tells me he loves me, holds me, kisses me etc. I just don't know what to do..I have talked to him but he just doesn't get that I am hurting to. He is my best friend..we are both in mid /late thirties we are not kids. I have had two prior long term relationships, and he has had two long term relationships. I just am unsure as to how to help him..I feel so alone..yet he is sitting right across the room. we don't fight or argue we get along perfectly.