Look RSF....for all intents and purposes, you have to proceed with the idea that your wife doesn't care who's fault it is anymore she just wants out. And the more you want her to validate you and take some blame here, the more she's going to say Screw it. I could not care less who's fault it is because it's all over. So STOP IT!
Do you want to know why you even start these conversations? Because you have some weird hope she's going to agree with you about something and if that happens maybe she'll agree to the big stuff, like reconciling. You're really going about this all wrong.
Stop R talks with her because right now, you're NOT going to hear what you want to hear.
You may have these conversations in the future, you may not. I just about fell out of bed when my H apologized to me. And even then he was apologizing for the pain he caused, not his actions. And I've come to accept, I'm never never never going to get that apology, where he admits his actions were wrong. Never. And because I accept this, I can move forward and we don't talk about it much anymore and I'm not waiting for any answers or apologies. It's done.
Now I just want to work on what got us to a point where he felt he needed to take those actions and put them into play so it won't happen again.
You do have some control here and you do have 100% control over you.
Stop starting these conversations/arguments you are not going to win.