i'm a therapist who specializes in treating moms with PPD and also PTSD (not just birth related). please know that you are not alone, and you will get through this. chances of PPD increase with the number of difficult experiences you have, and it looks like you have so many right now, it's no wonder you're feeling so awful.
have you ever heard of EMDR? it is a wonderful therapy that works well in situations like yours. it would help to clear the anxiety and trauma from your pregnancy and birth experiences. you can google either EMDR or "eye movement desensitization reprocessing" and find a practitioner in your area.
and can you get some help around the house? anything you an do to lessen your load is good (professional house cleaners twice a month? your mom or a friend to do laundry or shopping once a week? a night out with a girl friend?) please hang in there, mama, things will look up.
also, i wanted to say, you might want to talk about the klonopin with your doc. sometimes the side effects of conventional medicine actually make folks feel worse. there is a fantastic homeopathic remedy called COFFEA CRUDA and you can get it at whole foods. it works wonders for me when i can't sleep because i'm running over and over things in my mind. it is gentle and fast with no side effects.