Very sorry to hear about your situation- in the book "20 Years Gone: A Divorce Story" (out on Amazon and Google Books), the author, Dorian Wright, experienced similar issues of finding out that their spouse was a different person than whom they thought they had married.
I recommend picking up a copy of the book for tips, and also consulting a lawyer (which is also highly recommended in that book). That author's lawyer also recommended that they keep a daily log of oddities that they were observing, as that documentation could be used as testimony during the divorce hearing.
Thank you!
Our state is no fault divorce, so no matter what he did during the marriage, there was not cost for him.
I will read the book you recommended.
I always worry about him because he always said he was depression. And he always asked free time to go outside by himself to release the pressure . But the truth is, he was not depression at all, he was just happy with many other ladies when he went out alone.