At this point I don't think it is as much about what is "going on" today as much as it is what has already happened in the past
He just kept saying that I will not "let him in".
That may very well be true from his point of view, can you be OK with that?
It sounded like from what you wrote on TC's thread I think it was, by the time he had his last drunk you were already "done", and when he went on that drunk the switch flipped, the "I have had enough and I can't do this anymore" switch. That's OK, you are allowed to have that switch. You are allowed to care for yourself.
Then he decided to quit drinking to "save" the relationship and you stayed to see if anything had or would change. Like your feelings for him.
Apparently it was too little, too late.
You gave it a chance, you tried. It seems to me you waited to see if your feelings for him had changed.
You are not a failure, the marriage isn't a "failed" one if it produced beautiful children for you two.
"Hurt people hurt people" and he is going to be hurt right now, so is going to try to hurt you.
Can you be OK with that? Can you take care of yourself around that? knowing he is going to lash out and try and blame you and hurt you? That that's what hurt people do when relationships end?
It's OK to take care of yourself, to follow your own heart.
Anyhow, I'm trying to ask if you can take care of yourself but doing a poor job. Hang in there, it will all work out.