Very well said to say the least. I agree that the question "what are you depressed about" is horrible. I actually had a friend ask me "what CAN you be depressed about" earlier today. I was pretty upset about it, but I kept my mouth shut. Then he goes on about how he wants to go bowling tomorrow. Seriously--I can't just sit at home by myself without pestering the crap out of me? I usually don't give an answer when someone asks whats wrong, and just say that I'm fine. As you stated, unless you suffer from it, no one knows.
I hope that things get better for you and your husband makes an effort to try a bit harder to help you out. Again, great post and welcome to PC!