We live together still and I'm not sure how I should actually interact with her.
Don't react... pretty much ever ... unless she's running at you with an axe or something.
There's no point in having anymore R discussions, is there? Unless the point is to keep everybody all worked up and stuck in crazy world, there is no point, so just walk away and find something else to do like spending time with your kid, take the dog for a walk, and so on.
Respond respectfully to mundane items.
As bad as things are right now, and as much as you are ready to throw in the towel after all you have been through, you really don't hate this person or you wouldn't be here asking this question.
You don't respect the way they have been acting, and nobody can blame you. In order not to lose all respect for her, you need to minimize all negative interactions.
I am not asking you to be a doormat. Do not be a doormat. Just take the time to walk away from angry words, allow yourself to feel the anger they inspire, and then ask yourself if reacting in anger really serves any purpose.
If she doesn't want to end contact with a third party (EA/PA) and work on the relationship, then you should let her go (and offer to help her pack even), but you don't have to be nasty about it.
It is just something unpleasant that needs doing... like going to the dentist to have your teeth cleaned.
So... minimize contact. Support her efforts to move out if she doesn't want to work on your M, but do not discuss these things at any length. You are done discussing, and now it is all about action.
Keep sentences short and to the point, but be kind and firm. Give yourself as much space away from your wife as you possibly can so you can heal.
