My story is very similar to your though we have no children together. His second marriage and my first each with children of our own.
My BD was more subtle and slow but certainly reached a head in December. I had already been working and making changes and there was improvement. I saw the spark in his eye and he returned to hand holding and really asked to take it slow and it would take away.
But, I lack patience. I went overboard with my corrective behavior and he said he felt smothered. I called too much. I texted too much. I just wanted him to know that I heard his needs and I was ready to be the wife I was before again. All this he frankly said pushed him away.
Now he just wants out. He wants to be alone. He isn't happy or even likes himself anymore and states clearly that if he can't love himself he can't love me.
I know he feels trapped.
Everything I had read up to this point states not to separate and its better work on things if he is still in the home. He knows I do not want to separate.
I see my husband's struggles and his words are very close to yours though I'm certain he is not pursing a PA and most likely not a EA either. He just wants to be alone.
It breaks my heart in many different ways. I love my husband and to see him with his emotionless face - I feel his pain.
