Coming to terms with having Postpartum Depression

It's 5:30 in the morning. I''ve been up for over an hour praying for help. I didn't know why I was so different this time around. I had my son 6 months ago and it was a very rough pregnancy. I thought that I was sad and upset because of all the craziness I had gone through during my pregnancy, but this morning I realized it was something more. I have postpartum depression. I'm not ready to say it out loud or admit it to my husband or family, but I did email our mental health provider asking for help and an appointment. I'm crying as I write this because I am ashamed. I feel like I should be able to be stronger than this. I feel like an idiot. I feel like a failure. I definitely feel like I have screwed up the last 6  months for my newborn son and for my 3 year old who has had to deal with me being a crazy mess. I have tried so hard to overcome my feelings of anxiety, I kept trying to blame my feelings of overwhelming lack of control on my lifestyle. You see I'm self employed, my husband works a lot of hours, I have an 18 year old step daughter and I am busy. Never slow down kind of busy. But it isn't that. It's more. It's the anger, the frustration, the inability to control my emotions over little things. The breakdowns I have (and try to hide) over things that before wouldn't have made me blink an eye. I have always had it together. I am a planner, a perfectionist. I'm stronger than other people, in better control. Or so I tell myself. I'm quick to judge, but even quicker to try to help, to try to make everything better for everyone. And I've failed. I can't do this alone. I don't know why. It's just not working this time.