I like the words "life-changing situation" that Ann used. YOU no longer like the way YOUR life is going. YOU don't want to live this way for another 8 years. Even though you don't want the divorce, you have learned that for now it is the only way to stop going through these terrible, heart-wrenching, stomach-destroying experiences. It is the way to creating a peace and serenity in YOUR life, because YOU just can't take any more of those crazy-making conversations.
Fight for yourself. Create that calm place for yourself. Focus on YOUR serenity and what it will take to maintain it. You know that change is inevitable. At least YOU have the power to create the new change for yourself, the new life for yourself. Sure, it's scary to change, but anything is better than spiraling back down with your addict. Just as he needs to learn that life could be better if he just stopped using, you are learning that life will be better with no contact. Time for change.
And don't be upset with yourself. Maybe this is YOUR bottom. Maybe you are exactly right where you need to be to BEGIN the CHANGE.