Gal here, but I felt bad reading your post so wanted to offer my support.
Folks with an active drinking problem, alcoholic or not, have deep-seated issues which impede or prevent healthy relationships. It may be that not one side or the other is the “real” person, such conflict may just be who he is right now. I’ve been on both sides, with a drunk and have been the drunk, and it’s ugly.
Seems like to continue this you don’t get to choose one guy or the other, and it seems like it's not worth it to try to live with both. You’re already having to cope with divorce...having been there too I know we don’t end a marriage just to leap into more heartache.
Best wishes to you,
-bora