MLC is a very tricky beast because each crisis is unique to that person because of personality, childhood and coping skills.
Your h is most likely in the deep throes of replay and the ow is heavily invested in getting him to do what she wants, i.e., divorce you and spend all of his time, energy, focus and money on her. MLCers do tend to get worse when they are w/the OP, especially is they are being pressured by that person to get a divorce. Also, MLCers will become distant and in some cases disappear from the spouses, former friends and familieis.
In the beginning, about 12-24 months pre bomb drop, he had already begun to distance himself from you. When you were in pain and clingy, he felt guilt and shame for what he was doing to you and he didn't want you to know about the ow. Now, that things have changed and he has eyes only for the ow and you have been fired as his wife. In his eyes, his life has changed and unfortunately, you are not part of his new life. Yes, it hurts to hear this, but this is how they feel at the moment.
The best thing you can do is give him plenty of space and time. Continue as you have been, i.e., living your life to the fullest. One day, he may wake up and realize that he is very close to losing the best part of his past life and that is you. Stay strong and keep the focus on you.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.