As others have already said. I agree with the fact that you need to take care of yourself first and foremost. That is #1. Your happiness should not be determined by the actions of your husband.
Your husband sounds a lot like me and others. Selfish and self-centered to the max. I, too, would do all the lip service in order to get people off my back. I would make promises I wouldn't keep over and over. This went on for a long time. You said you know what he is doing, protecting his drink. That's exactly it. I did it for a very, very long time. I was searching for an answer to be able to do it on my own and a reason why I was so unhappy without having to give up the drinking. I was convinced in my mind that there had to be something else causing my unhappiness. I truly thought it couldn't be the alcohol or drugs, because those actually arrested the depressive symptoms temporarily. But it was just that, a temporary fix to a permanent (at the time) problem.
When I was drinking, I couldn't control how much I drank, and when I wasn't drinking I was obsessing about it and very restless, irritable, and discontent with life. Then I found a solution. My solution happens to be the steps of AA. It works for many people, but there are other methods that work for others.
Generally, if he does go to out-patient treatment (which seems like the most logical and path of least resistance at this point), they are most commonly 12-step based. They will once again suggest complete abstinence from alcohol and he start the program. You will truly see his commitment to this at that point. All that is really needed at that point is open-mindedness to the fact that he cannot do this on his own.
I wish you the best.