Posted this in mental health but no responses. 
I am due to have third baby soon. I think I had undiagnosed pnd and birth trauma after dc1 but felt better after about a year. Much of it was characterised by being very anxious - I felt that if I did not worry constantly then something bad would happen - kind of payback for letting my guard down. In part this was because dc1 was poorly when born and also because she had an incident on first night where I thought she had died, until I found her in the resus room with the midwives, alive and kicking - and I felt I had taken my eye off the ball (a passing midwife had spotted her turning blue I hadn't). In part this was because she took a long time to conceive so I never really felt I'd get a baby, having yearned for one for so long, and then I thought I may be punished for my happiness by having her taken away when I got her.
Anyway this led to a rocky first year at times but I got some help from a mate who works in birth trauma, and never went to gp about it, and slowly felt better, especially after a year when I started to get some sleep. DC2 was textbook birth and relatively easy beginning and mitigated all the fear of dc1 really, and I also did that chat with the hospital where you go through your previous births and they explain what happened and I felt very calmed and measured by midwife telling me that would have noticed my daughter turning blue, she is sure of it, and coughs would have alerted me shortly after midwife noticed and I would have saved her myself.
But now am 37 weeks with dc3 and feel anxious all the time. Not helped by having gestational diabetes and having been told about the higher stillbirth risk. I can't stop worrying - feel like I might bring disaster on myself if I do stop and be punished somehow for not worrying. It's like the worry is the only thing keeping the baby alive, though I know this is silly. Also not helped by baby being conceived at time when dh and I were not having a great few months and I wasn't sure to start with whether I wanted to be pregnant or not (even though we were trying...). And it has been a tough pregnancy in terms of sickness etc and I have felt rotten, and then worried the baby can sense I am a bit indifferent to being pregnant.
Sorry - am just ranting. Feel exhausted by anxiety. And really not keen on going to gp. Don't have time anyhow - so many gd appts, extra scans etc, and dc1 just started school and trying to fit all in with drop off and pick up and looking after dc2.
any advice.... help me calm down