i'm a recovering addict and if you only knew how strong the pull of addiction is, you'd still may not understand the mind of an addict. most of the time i was in active addiction, i didn't want to be around no one who could remind me of how destructive and unmanagable my life had become. its like while in the throes of addiction, the desire to use takes over every waking and sleeping thought. try not to take it too personal. he may still show up one day for a round 2, so maybe you try to focus more on you and how you can make your life better. i know it hurts, been there. my ah has walked out many times leaveing me feeling a lot like you do right now only to eventually try to lie away the hurt and confusion only to do start the cycle over again.
maybe you could try to just except the fact that he's an addict and his behavior is what it is, addictive behavior. i know its hard, confusing and sad but you can get through all of this. try to do whatever you have to to keep from thinking about him and his behavior, one minute/day at a time. it does get easier.