Yup. I've gone (and still to am going) through the same emotions. It took me roughly a year to come to the decision to leave and divorce. One reason it took so long was dealing with all my issues of having a second failed marriage. I truly meant my vows and had to struggle with whether my personal understanding of God allowed me divorce as an option. We have only been married 4 years and have no children together (thank God I am too old for that particular problem to have been possible) so its a bit different for those who do have kids with their A.
It hurts that the marriage I thought would be for the rest of my life ended. I am mourning the loss of the relationship I thought I had. I am incredibly saddened that AH will not work on his problems and can only go further downhill over time.
But I have also come to recognize that I never should have married him at all, that I did it for all sorts of wrong reasons.