Well, I think the behaviors you describe are part and parcel of addiction, but does it really matter? If the behaviors are there because he is an alcoholic, sociopath, spoiled brat, or raging lunatic, they are still behaviors you cannot tolerate, right? So whatever the cause, in the end you're still left with what you accept in your life.
I used to try and figure out what my husband was thinking, why he did what he did, and it was a huge waste of my precious time and energy. He does what he does and only he has the ability to figure out why or to change it. Now I focus my energy on figuring out why I do what I do and what I can do to change it.
Best wishes to you and your children. They need at least one stable and sane parent and you are stepping up to the plate for them. Way to go!
L