Okay, this is going to sound very harsh toward your XH, but I gotta say this ....
He sure doesn't like to take any responsibility for his shortcomings, or his bad choices. He seems to like to blame others for all his problems. This is the second M he has been manipulated into. Good grief! Is he so weak that he can't say 'no'!? Truly, do you really want someone like this in your life? I know you love him, but the person you love seems to be a ghost, and he has reverted to his lowest common denominator (seems you got the best of him in the last 15+ years, so be thankful for that). He says his first wife had affairs, but he chooses to do this himself. Somewhat hypocritical, I think. He has proven himself a liar, so how can you know that he wasn't the one having the affairs with his first wife? How can you know that anything he said was the truth?
I am sorry for your pain and devastation, but please keep moving forward. You may be wasting a lot of time, hurting for someone who most likely never, truly existed (I honestly wonder if he really is in MLC, or this is just the real him). Be happy that you had those good years together, and that you don't have to be with the bad part of him. His OW/W gets to put up with that. You were a loyal, good wife, and you can be that again for someone more worthy .... one day. You didn't deserve this, but bad things do happen to good people. God doesn't promise us easy, and he cannot take away someone else's free will, so cannot force your XH to love you, and come back to you (well, I guess God can do anything, but I doubt He would go against our free wills). What He does, is send the Comforter, if we will accept it, and give us peace if we want it. He will no more force us then He will force our estranged spouses. So, pray for peace, for patience, for letting go of the past and moving on. No-one can say what the future holds ... we can only live in the now.
I know it's hard not to obsess about your XH's remarriage, but try to put all this out of your mind. It is, obviously, beyond your control.
Sorry, if I offended you in any way. Just take this as a 'gentle' 2x4. It's good that you can vent here, and get it all off your chest.
Take care.
Me:57 H:52 M:28 Got another lawyer last year and filed. D35,S/D twins28,D22 EA4/04 End? Who knows? "Life is like a mirror. Smile at it and it smiles back at you." — Peace Pilgrim