There are a few of us on here - Rhubarb by far the most extreme
I had it with both pregnancies... DD, I put it down to work stress, hg, surprise at pregnancy etc. I hadn't heard of AND, just assumed it was hormones and all of the above.
DS came along... planned, wanted, stable life, and then I fell into the hole again. I would have normal days, and then big black stretches of despair - hating myself, my life, feeling guilty at feeling that way, wanting to end it all.
The biggest help I found was honesty, and using the scarey "D" word. Once I told my family and close friends how I was feeling, and used the word depression to them (which seems to make them stop and realise we're not talking "a bit low" here), I felt a lot better. It meant I had people to turn to in the darkest days - people I could cry big snotty gaspy tears on and who could help carry me through.
I started an AND antenatal thread on here and there were a fw of us going through it together and supporting each other.
I was honest with my midwife too and she was lovely - she told me that she was there to support, that there are things you can take if you think you need them.
But yes, honesty is the biggest thing - your DP needs to know exactly what it is and how you are feeling... they are much more help when they know than when you're just seeming like a bitch
Feel free to email me if you want to chat flamesparrow at gmail dot com