Ironically, my ex volunteered to be the case study for a research project at my college on addiction. Basically, what I've learned from him, and others who struggle with and treat addiction, is that my field, behaviorism, is left out...you have to find something more gratifying than substances, set a goal, make a plan, and both self-monitor and have someone monitor you. I like AA and NA sponsorships because they help keep people on the right track.
My biggest mistake in this relationship is thinking, esp. since we are long-distance, that I could monitor a "behavior change plan" for him. It's not like when I'm in a classroom, clinic, or local home, where I can track progress, intervene, model behavior, etc.
A good friend, a crisis nurse, is on the edge of divorce with her AH. She said the definition of irony is that she and I are damn good at our jobs, because we have that "professional objectivity", but, when it comes to picking mates, that goes out the window!
We've come up with a saying...."we love our jobs so much we took our work home with us!"