Des, can you check out the county mental health center? They are often free and while it might take a bit to get in, once you are in the system, it's easier to get appts.
It did affect your babies, I'm sure, but you have not destroyed their lives at all. For me, when I was feeling awful, it helped to completely focus on my children instead of me. While it might have just been a distraction, we all benefited from it and my children and I have a wonderful relationship because of it.
Hang in there Des. I hope you are able to get some help.