"i insisted that W got a boarding room in the nieghborhood so she can come around anytime she can. I suggested she come around and have breakfast with D8 once in a while or even come by in the evening for story time before bed."
Wrong call. You don't make those arrangements for her. You tell her when and where she can meet your daughter and it's up to your W to take the initiative to meet those times. Don't 'insist' that she have any sort of living conditions close to you. That's her issue to deal with. If you continue doing that, your W is going to accuse you of 'controlling' her life. It happens all the time.
"At that point, I will absolutely get C for D8."
NO! The point for you to get a C for your D8 is NOW. Your W is out of the picture. That's alot for an 8 year old to process. And right now you're not processing things correctly to begin with. Put your D's welfare first. Talk to someone about her so that she doesn't become a casualty in this whole mess.
"We all lose but my little girl lost the most and she's part of the reason I'm not giving up on W. "
Forget about your W right now. If a mother can walk away from her child, there is absolutely NOTHING that you say that will convince her to stay. Just concentrate on your D8. Right now you must show her the love of two parents.
M-43 W-40 2D - 9 and 5
Emotion, yet peace. Ignorance, yet knowledge. Passion, yet serenity. Chaos, yet harmony. Death, yet a new life.