I'm really sad because I've come to terms with the fact that my brother is too far over the line to save.
That sounds very stressful. Why do you think you can't save him?
His behavior is out of control, he has no respect for any of us anymore. We just can't be around him.
I understand that sometimes things can seem hopeless. It might be best to take some time for yourself and regroup your thoughts about the situation before deciding what to do. In the mean time you should still keep an open line of communication available for your brother in case they want to get help.
It would take our entire family to try to intervene and get him the help he needs.
I think you should keep trying and not give up on your brother. If you give up on him, you'll never forgive yourself.