Hi boss, as counter-intuitive as it may seem-- this is pretty normal. Once a woman has a baby, the calculus of the marriage changes enormously. Through divorce, she will be entitled to child support, alimony, and she has now reproduced, and may want to take that child to a higher status male.

What I'd like to tell you is, things will eventually get better.

What you're describing happened to me but more at like T+nine-months. I had supported my wife for a decade and caught her cheating. That's, normal. Sadly.

Despite being my daughters primary caregiver, i wasn't able to see her for about 5 months due to the inequity of the court system. It was terrible, but I got through it, and she and I have a wonderful relationship now.

Play the long game, worry about your welfare and your daughters first.

And if you need advice or would like to talk, indicate so and I'll get you my contact info.