Wow. Reading all this above reminds me all over again how hard marriage/long-term partnerships are. I am sorry for everyone who is struggling. I have been there. That said, @
Seahound, it really sounds like you have come to a decision. You're just having difficulty figuring out how to communicate that to your wife. I wonder what you therapist says about you sitting your wife down and telling her you're leaving. Have you had that conversation?