For me and my recovery, it was a series of small shifts. It wasn't one thing that clicked, first something clicked and then it was click!click!click!click!click!click! And then there was no going back. It was like getting glasses -- I had no idea my eyes were that bad until I could see clearly! Then I mourned all the lost time and opportunity. I feel pretty good now.
Regarding my AH and his behavior, I took a chance with the SR advice, took an emotional step back from his drama, and gave myself permission not to freak out over his every move. When he drank, I made him leave the house. Over time it became very routine. This was just his pattern, I accepted it. One time he left and I just said no more, and I changed the locks on the doors. I haven't let him back and I won't because I will no longer accept this kind of treatment from a partner.