Busting, I like your goal to preserve the R your H has with the kids. Your fear about the NC? I can see how you feel this way. But there's no way there can be absolutely NC because of the children. So keep doing what you are doing and stay on track by writing here.
You've grown a lot during this time, and I know you can see that. Feel good about yourself because you've given this your all and continue being a wonderful mother.