I am sorry too that you are going through this. But always remember that you can make it through anything, even this.

Maybe I missed this somewhere, but does he live with you and the baby? If he does, and he leaves for work on Friday and you don't see him until Sunday, this is unacceptable. If not, it still sucks.

Remember you teach people how to treat you, accept this behavior now and it will only get worse. Also keep in mind that if you are going through real PPD, get medical assistance. He could just be shying away from you because of your negative, depressed energy. (but still that is not acceptable)