Speaking from someone who faced the exact same thing.
I am divorced now, have been since December 21, 2007.
He needed to end the marriage.
He is now slowly waking up, being much more civil and starting to see some positives in me.
I have GAL, am very active, and continue to maintain my home and children.
Relationship with OW is fading, lust is going away, she is becoming more controlling as he shows more interest in his family and me.
He needed to lose the marriage and continue the mid life journey.
Financially take what is best for you. Always though make it clear this is not what you want. Go dark after the divorce. That is my opinion and what has worked best for me.
Me: 46 H:44 Together: 25 years Married: 20 years Separated: 11-30-06 Divorced 12-21-07 OW: EA began 2005 PA began end of 2006 3 children,20, 16, 6 ex asked for forgiveness 01/16/11