Bacarver, I have a close friend who had an adoption that did not work and was later rescinded, and have worked with a couple of parents who have experienced this. You are definitely not alone. Let me check with the close friend when I get back to work next week to see if she has any support group info---she may well---or other resources for you. I am sorry. Very painful stuff. Please know that with the best will in the world, you can't always make things work for other people, and that this is not your fault.
"My predominant feeling is one of gratitude. I have loved and been loved;I have been given much and I have given something in return...Above all, I have been a sentient being, a thinking animal, on this beautiful planet, and that in itself has been an enormous privilege and an adventure." O. Sacks