You are far from detaching and that's to be expected. You have a constant reminder of your H growing inside you, not to mention a biologically driven need to keep the family unit safe.
Just do what you can, I think you are amazing. You're taking care of your kids, got anew job and are maintaining equilibrium.
Why he would talk to you D about his R probably has many reasons. But no matter the reason, it's not good for D. Maybe you could have a talk with her about how to cut those conversations short? "Dad, please don't talk to me about your R with OW." Maybe the IC can help with this.
((((SB)))
Me 57/H 58 M36 S 2.5yrs R 12/13
Let me give up the need to know why things happen as they do. I will never know and constant wondering is constant suffering. Caroline Myss