I had it bad after my first, and had a much easier time after my second (still weepy/hormonal times for sure, but nothing that felt overwhelming and insurmountable like the first time). The circumstances of those two pregnancies and births were completely different for me, though. First time was unplanned and it was quite devastating to get used to the idea of being pregnant. It was very bad timing for us, as I was working full-time and trying to finish my master's thesis so we could move across the country when my husband graduated. Then we moved 3000 miles away from everyone we knew (except my BIL, who doesn't count because he's completely self-centered) when I was 30 weeks pregnant. Add in a traumatic birth and complete social isolation and sleep deprivation for the first year of my son's life, along with a husband working ALL the time to get his career going, and living with my a**hole of a BIL and you have the recipe for terrible PPD.
The second time was a planned pregnancy, I had friends, my husband was working a much more sane schedule, and I took lots of fish oil after the nausea subsided. Also, I got more sleep the second time around and that made a huge difference, I'm convinced. I had such horrible nipple trauma that my lactation consultant recommended resting one nipple completely (just pumping) for a while, so I would pump before bed and my husband got up with the baby and gave her a bottle. She slept longer stretches early on than my son anyway, so I ended up getting 5-6 hour stretches every night! Awesome.
So, I know I'm more at risk this time than the average person because of my history, but I'm trying to focus on the factors I have control over. We'll find out soon enough...this baby's due in less than 2 weeks now. I am also probably going to have my placenta encapsulated this time, too.
Oh, also...I have recently been taking Hyland's Insomnia remedy and it's worked really well for me. It says something on the label about being for insomnia due to stress and worry (I was lying awake for hours, trying to shut my brain off & it just wasn't working). And I've given my daughter Calms Forte (also by Hyland's, I think) when she's had trouble getting to sleep as well...doesn't work as magically as it seems to for me, but seems to help sometimes.