My DH has never hit me and is the kindest man I know. However ever since bringing our DS home he has changed. He gets stressed when our 6 week old cries to the point of "spanking" him. Last night he came to me crying saying he hit him again. He says he never does it hard, but I am obviously still upset. I tell him to come get me when he feels that way. He thinks DS hates him and I think he has the Postpartum depression. What should I do?