Rexgem makes a great point. And I think it's one Artista has been making.
If she fights for you even though she truly thinks you moved on and lost you and you were gone (much like artistas H was) then you know it is genuine. Not just guilt or losing her cushy life. If she still wants this marriage to work even though you are DONE, then it might just be genuine.
And really, like coconut said, you are concentrating so much on her, wht she is thinking, how she is acting, and you kind of have been all along, you have neglected how you feel, how you are hurt, what you want and what you need.
You need to take the focus off her and place it on you.