funnybunny, are you getting any help or treatment for your depression?
I have been in a similar sort of situation. I had terrible pnd, although i wouldnt accept it or get help. I completely changed, was awful to DP, who in turn, was awful back. He said to me once, that every time i was shit to him his feelings for me lessened, that i he couldnt look at me and that he had nothing left. He was crying when he told me this - i begged him to stay, for DD, and a YEAR later i got help for my depression. We are still together, he loves me, he never stopped loving me - is he in love with me? I don't know. But i love him dearly, he is my soul mate, and i his. Without ADs i would have lost him. DD is nearly three now, and i think THINK we are in it for the long run, incedentally, we have been together 16 years too.
I just think that your DP is floundering, he doesnt know what to do to help you, he may not even recognise you need help. Of course this isnt all down to you - its not a question of blame, it could well be that he needs help too. I know my DP did but would never accept it. Things change when you have children, and i think when you have been together a long time before children that change can almost be harder to adapt to. We were exactly the same, the envy of all our friends with our rock solid relationship. Well, we are still together, but "in love" what is that anyway? honestly? It is unreasonable to expect your tummy to flip every time you see your partner, for the sex to be explosive etc, is that what he misses, i know i do. But it is replaced with something stronger, i just wonder if that transition is hard to get through.
Give your DP some time and space, don't bug him with questions. I remember speaking to a close friend of mine who had been working with DP during a really rough patch, i remember saying to him, look, DP says he loves me, but i need reassurance. HE said some wise words, tough, you cant keep pushing, you need to give him some head space.
Im waffling because im tired and ill (d+v). But i dont think this is the end, but a sign that you could both do with some help here.