When we told our kids that we were separating, I cried and my wife sat there emotionless. They were upset to know that my W would be moving out. Had you asked my kids for their preference at that time, they would have preferred that I move out. But SO much has changed since then. My R with my D's has become amazing. My W started out doing a lot of things with them and they would go over to her house to spend the night on weekends (I insisted that they be home with me every school night since I take them to school in the mornings) but over time, she has really dropped off in the amount of time she has spent with them. My kids now who their rock is. They know I am the one that will always be there for them. Her interaction with them in the past month (since I filed for D, A got exposed to OM's W and we started piecing) has actually dropped off even more. They've not stayed the night with her even once. But I think all that is ok. My W is busy coming to grips with what she did and how much that hurt everybody. She needs some time to figure out how to make amends for all that. She'll be moving back in soon and we'll work on rebuilding our family.
I would just say that you should let your W put any of the blame on you. When we told our kids about the S, I allowed my W to say that WE had decided to S when in fact it was solely her decision. I would insist that you W tell the kids that this is HER decision. Then you just need to work on being the best dad you can be. It will be hard for the kids but they are resilient. They just need to be loved.
Me: 48 y/o W: 47 y/o Together: > 20 yrs BD: Dec '15, then S 2nd BD: Mar '16, then I filed for D April '16: started piecing