Robin, I know we have talked privately, but I just want to tell you again how much my heart goes out to you. I remember we had something similar happen in 2008, for so long after, every time I had a chance to think, it felt like someone slapped me in the face. So painful, and so many emotions for us.
My vet gave us some good words, that maybe will help you. He was trying to help us with our sweet, show / drive / love / pet Goldie, and when it was to no avail, he told me "you bred her because you or a friend would have loved another horse just like her." And that is so. You never know how things will come out, but if not for how special a mare is, people like you and I wouldn't have bred her in the first place.
If I could give you a hug, I would now. Sharing your tears, and I think a lot of others of us here do as well.