I've only got a sec right now. Can you do nothing for a bit? You told her you want D. There is no reason to reiterate that.
What you really need to deal with are the logistics and boundaries (she can't keep pulling the last minute stuff etc).
You have the same issue today that you came onto the site with which is separating the two issues, your R with her vs. your agreement regarding the kids.
You say you can't take this anymore so as opposed to repeating that you want to end it (which is not actually possible), you have no choice but to deal with it...meaning, what relationship are you willing to have under the current circumstances? What are the boundaries between the two of you and what are the logistical agreements that you stick to. That is where your focus should be.
