Oh, dear! I'm so sorry!
I'm so sorry to hear that! We've been through the same thing (almost twice). The birth mother changed her mind 3 days before her due date.
It's a loss that no one can understand unless they've been there. Allow yourself some grieving time - this is considered the same grieving as a late term miscarriage so don't allow anyone to tell you it's not a big deal!
My only advice is to go take a vacation and try to get some downtime with your husband.
Sending prayers your way!