I had a rough road as well and it took me a long time to get it right, if I ever really did.
Anyway, I think you need to deicde what you want. I know it's hard when you get conflicting advice but if you've read from Sandi, who has a lot of insight into the mind of a WAW, you can see why what I'm advising you is important.
Yes it may not save your marriage but it will save your sanity. I do want to be clear that I really do think you need to coparent and get along for the kids. Who knows, if you do D, you may be friends down the road. But is what your W done something you would want in a friend right now?
And I will still stand by my statement - she needs to feel what it's like to not have you in her life. Right now she is cake eating.
Enforce a boundary and stick with it. Limited contact except regarding the children. Stick to what you stated as a boundary and eventually it will come naturally to you both.
As far as my sitch, I decided my Hchose to remove himself as my husband but he was still the boys father. I was going to be friendly and nice for the kids because I was the bigger person. I also wanted to be the person only a fool would leave.