Life, 25 gives you great advice, and I agree with her.
MLC takes a long time. A really long time. Drinking, as far as i am concerned, is a symptom that all is far from well, but as I understand it, in your case this predates the actual MLC. So he has a further issue to deal with, drinking and the OW.
He may change, but I suspect it will take a long time to work through all of his stuff. What we are urging is not necessarily to give up hope. That is your choice. But take the focus entirely off your h and place it on yourself and your own journey. Make it a great journey. If he ever wants to rejoin you on it you will be in a sweet place. Focus on getting to that good place as soon as you can. The length of time varies for all of us. It is when we are on our own, and full of joy. Not saying you won't meet someone else, but we absolutely need to learn to be alone and like it.
it is attainable, but it is hard journey. You will get there.
