Tom, very sorry about the disclosure of the A, I know it's a gut-bunch (believe me, I do know!) but at least you know and can quit wondering and spinning scenarios. Also I think you're doing the right thing in giving yourself some more time on the D. In a month you'll know better where you stand.
I would suggest cutting ALL contact with W except for whatever minimum is required for coordinating D's needs. If she texts asking how your day is going, or asking a pointless question, don't reply. She needs to know you are not Plan B and you are not going to be her BFF.
