Agreed with all except one suggestion. Reality shows are not real. Intervention is for the sake of drama. Or feeding on the desperation on the part of family members. I believe a VERY small percentage stick to it. You can't force people to change. I believe the reason for many failed marriages is the notion that you can change or "fix" someone.
No one changes unless they want to change. This is true of addictions, weight issues, emotional issues etc. You only loose weight when you decide it's time for a change. Same with drinking.
Living with a destructive relative, you have two options. They can be miserable or you can be miserable with them. You need to focus your energy on Cameron and shielding him as much as possible from this destructive behaviour. Intervention isn't going to work and will only reinforce their notions that it's you and not them.
Move on and focus on better relations with your loved ones.