You have got to figure out a way to detach and not react emotionally to this stuff. If that means turning ALL emotions off, then do it...at least for now. You need to get control of yourself ASAP.
^^^^^^^^^^^^^^^^^^^^^^
Right now your emotions are controlling you and nothing good will come from that. I understand how much it hurts and how confusing it is but nothing you say right now is going to make a bit of difference, especially with your emotions where they are. You need to create some distance and avoid all these types of talks at all costs.
You said you wanted to breathe and slow things down...so what's stopping you???
You don't have to engage in these talks, seems you initiate many of them. You don't have to discuss D, try to figure anything out now, help W with any of it, or go to a counselor/ therapist until you are ready. If she wants this so bad let her do everything and (most importantly) act as if you're fine with it. You love her enough to want to see her happy.
So what plans do you have this weekend?
Personality is who the world sees, character is who you are