You sound to me like a woman who knows what she's doing. If my husband was in any way physically abusive I would also slip away and get MY act together without giving him a head's up.
Keep posting! Always someone here. I hope you can get into a program soon. Don't forget you can go to an emergency room for alcohol detox if your blood pressure goes up OR if you have increased anxiety and nervousness.
Good for you that you see the handwriting on the wall and are taking care of yourself and your kid. You Go Girl!