Chris, I'm not one to usually tell or even recommend to someone what they should do, I'd rather take the approach of asking questions and letting people figure things out for themselves. With that I'm going to take an exception here, please don't get upset...
I don't think you're ready for this conversation yet. From what I've read (I think I've read everything you've posted) I'm a lot like you so I say this from experience. You're already worried about a talk that's 4 days away which makes me think you aren't ready. You'll know when you're ready.
Ask yourself this, will having this talk now, Thursday, or even next week help YOU? Like others have said, if it doesn't happen now, if your W wants to talk it will eventually happen. You have lots of time even though it doesn't feel that way. Use the time to fix yourself and make this conversation really worth it to both of you.
Personally, I think for this conversation to be beneficial the following things need to be in place (yes they're all interelated): (1) You need to KNOW you will be able to STFU and listen to her (2) You need to KNOW you have your emotions in check and have the discipline to keep them in check in the middle of a $hitstorm (3) You need to be confident in who you are (4) You need to have more distance between you and W. Going in to this talk you need to convey you're fine with your life and you know you'll be fine no matter how everything works out
Personality is who the world sees, character is who you are
