So sorry about your S and his experiences with the daycare. He probably needs the support from your W which he is not getting. My D6 loves daycare but sometimes she will tell me when I'm neglecting to pick her up to start picking up the slack and maybe once in a while pick her up from daycare.
I can relate to your story about providing for the family after the marriage. I was too caught up with not messing up with the bills and the financial situation that I neglected the fun side of having a family. As a result the W dropped the bomb. We're ok now - better than when we started. I just have to remember to have fun once in a while and to just let go.
Good luck with your present sitch. Your W's willingness to fix the R is a very positive sign. Just listen and validate. It might not turn out after the guilt has subsided so well so just be prepared for her to pull away.
Me: 40 W: 39 D12 D9 D6 ILYBNILWY: 06/15/07 "We can work things out": 06/21/07 Currently: Still together, DB'ing every day