Let's analyze this without all the emotion. You are expecting an active alcoholic to prioritize his budget so that groceries come first and booze comes after. And now you're angry because he didn't.
You have a non-enforceable agreement with an active alcoholic, which makes you financially dependent on him. And you get angry when he breaks the agreement.
So, as long as you are in a situation that requires an active alcoholic to "do the right thing" you will continue to be frustrated, disappointed, and angry.
How can you change things so that you are no longer depending on him for your life to run smoothly?
My first thought is to get the court involved. Have an enforceable order for a smaller amount seems preferable to having no ability to enforce anything. It also seems to me like visitation orders in place that do not allow consumption of alcohol within 24 hours of visitation would take you out of the "police" role and make him answer to the court.
I don't know about your state, but here in CA, the amount awarded in a divorce is directly based on the amount earned by each spouse during the marriage. So, you may actually be hurting your case by earning more money prior to divorcing him. I strongly suggest seeking legal advice before you end up making things worse for yourself and the children.
L