Holy crap! What will you do when a person dies? Get a hold of yourself. It is sad, but it's part of life. And yes, I've had a pet get hit and killed - my last dog. Not only was the poor little dog dying, my daughter was screaming (along with the two friends she had over our house to play) and the boy who hit her was crying.
My point is that things could be worse. Stop feeling sorry for yourself. Your cat is dead; not you.