Welcome to the Board. I'm sorry that you have to deal with the horrors of a loved one's addiction, but I'm also grateful that you've found us and have taken the opportunity to post. Other members will be by to greet you, but as is my wont when greeting new members, I'd like to share some of my own thoughts.
I have learned to protect myself for the most part but my biggest issue (for myself) is finding a balance between supporting my parents, helping my brother and not driving myself and my spouse absolutely insane in the process. How do a continue to be a good daughter and sister when my parents are constantly enabling my brother to basically kill himself? My brother is emotionally and verbally abusive and has hit me before and its VERY hard to be around him. he is volatile. i know they are scared but what is the "proper" response for a sibling in this?
This presumes there is a way to "balance" all of those things. Is there? Perhaps. But the question you have to ask yourself is how far are you willing to go to see if there is.
You have 7 years of evidence that your AB is not interested in pursuing recovery. There's nothing you can do to help him. And there's really nothing you can do to help your parents deal with him, either. The best way to understand that is to read as many posts as you can by our residents moms. Two of those moms that come to mind are Ann and ilovemysonjj. But there are others, all in various stages of recovery and sanity. Not to steal Ann's or ilovemysonjj's thunder, but I think they had to go through the "enabling" process with their sons in order to understand there was ultimately nothing they could do for their sons. And that's a hard, sh!tty, painful lesson to learn. Your parents will have to arrive at that place, too.
One more thing.
Verbal and physical abuse are unacceptable.
Period. There is nothing that says you're under any obligation to put up with that. If he ever hits you again, call 911 and let the police deal with him. If your parents get upset with you for doing that, that's their problem. All you can do is watch yourself and take care of yourself. That means establishing boundaries.
Keep us posted. And again, Welcome to the Board.