Don't really know what to say - my OH must have understood, or at least kept his mouth shut!!
Can he come to GP's with you?? Perhaps hearing someone else acknowledge your problems may help
I'm sorry you are depressed. Perhaps if you are finding it hard to explain to him how you are feeling you could get him to find out about PND through reading about it himself. Then once he understands more about how it affects women, he can apply his knowledge to how it is affecting you personally. It is obviously a hard time for you; and probably quite overwhelming for him too.