I had PPD with #1. Depression runs in the family, and like you we had alot of situational things going on with us (loss of job, possibility of moving, etc.). I didn't admit to it until he was 5 mo., but I probably knew I had it starting at 2 or 3 mo. post partum. I just never felt like I was getting "over the hump", and that the end was never in sight...I know everyone sort of feels that way sometimes, but I was hopeless. Got on meds and was MUCH better. We moved closer to family and I got some support and got even better. Started sleeping again.
With #2 I was going to start meds asap. At the last minute I changed my mind. I told my parents and my husband where the drugs were and hoped that I would be on the good side of the 50/50 chance of getting it again. Because of the support and "letting go" of taking care of the baby, not to mention my lucking out on him being a good sleeper (5-6 hrs straight from the get-go!), I didn't get PPD again. I did get some "blues" around the 3-4 week point though. I think by that point the sleep deprivation is setting in and the reality of "starting over" with an infant starts to weigh on ya. I got better after that though. Still had some tough times, but I was more willing to take a break and hand the baby over when I needed some space, etc.
If we ever have #3, I must be honest and say I will 99.9% be sure that I will be on meds. I think I got lucky with #2, and #3 prob. won't be so "easy"...not to mention going to #3 is a whole new ball game
I tried all of the homepathic and natural remedies out there...I think I had some serious probs. Western meds were great for me. I still get flack from my natural birthing mommas in my town, but oh well, they don't know what its really like.....
OH - I went to my family physician to get the meds. NOT my OB.