It's been 9 years
and you're still crying over a horse you lost that long ago? Maybe you need to see a therapist. That kind of grief simply isn't normal.
It's okay to feel sad and maybe get a little misty eyed on the anniversary of a much loved animal's death, but after 9 years I'd think you'd have learned to live with it. My heart horse has been gone 6 years, and I actually forgot the anniversary of his death this year. That means I'm healing and moving on, which is how grief is supposed
I also have my doubts that a vet would call a 13 y/o girl and tell her that her parents said it was okay for him to 'kill' her horse, or that he was going to sue a child for slander. That simply doesn't pass the smell test.