GET HELP! Talk to someone, anyone, but hopefully reach out to a trained professional.
Get rest when you can. Seek to take care of yourself, even if you feel like you can't lift your head off the pillow. Try to exercise and eat right, take vitamins, and if need be, find a medication that will help through the darkest times. Find the right combination that will work for you.
Try to stay active.
And try to turn any resentment you might have towards your children into a focus for being. See them as a reason to live, a reason to heal.
And let go of the anger. Under the anger is a lot of pain, but you have to peel away those layers before true healing can begin.
Remember you're not alone. Ever.
Finally, accept it. It took me a LONG time to accept that PPD invaded my life. That it changed my being. It changed who I was, who I am and why I'm here. Once you start to see light, once you start to let go and find some strength again, begin to understand that even in your darkest hour, there are things that happened that were good. Pull from those moments. Recreate the happiness PPD tried to take away. Remember the first smiles, the first steps, the first tooth, and know that once the cloud has been lifted, those memories are once again yours and no one or no disease can take those away.
Recovery from PPD long and bittersweet. Those nice memories don't come easy and you have to dig deep to find them. But they do become a defense against PPD when it tries to creep back in.
And it takes time. The scar will be there. While I no longer have PPD, I still have the scar and it will be with me forever. The key is not letting it win, not letting it debilitate you and your family, to not let it take away any more memories or minutes from your life.