I am just now reading this thread, and what a great post this morning. GOOD FOR YOU for finding your own self respect and kicking this jerk to the curb. Trust me - you are doing the right thing. Remember this, and save this thread somewhere where you can refer back if you even feel weak or confused. Memorize what folks say here, because they are absolutely correct.
Not only that, but you have no guarantee this guy will get sober and be a good man. It is likely he has far deeper issues that alcohol suppresses. That's the sad truth with alcoholics. There are issues and personality quirks that often make them great alcoholics to begin with.
You've got an opportunity to be a great Mom now. Take it and run. We don't get do-overs with our kids. So put this role first and foremost. You will never regret that.
Peace,
~T