I am glad to see that you started a new thread. Your a wise man and there is a lot in your posts that others can learn from(me included).
The anger and rage in your STBX is something that you cannot control. It sounds like you are doing your best not to get dragged into it. It's best for you and your children that you not get dragged into her drama. Of course everything right now is about you and how you are punishing her...how you drove her to this state.... I'm not saying you were a perfect H, but she is accountable for her own words and actions...not you. To me the small gestures that your W is showing, like dinner, is her trying to be cordial about the realities of your sitch. Hopefully she can keep the drama at bay, really I hope she can step up and do what needs to be done to stop the D, because it is best for everyone.
If your sitch ends anything like mine...cooler heads will prevail. Not to say the drama and the blame wasn't there but it was kept out of the business of D.
Keep your focus on your kids and take care of yourself. Your in my thoughts and prayers.