So let me get this straight. Your W is having an A but the problem is that you are likely gay? Nice. If you want to remain friends after a D, that's fine. But if not, you should tell her that's not how it will be. Lost, I see that your W is VERY conflicted based on the things you are saying she says. That is a good thing when it comes to having a shot at saving your M. BUT, her world has got to come crashing down around her. The sooner that happens, the sooner things can start to turn around. So let her see you walking out the door. Let her know that you will NOT be friends after a D. Let her know that you will NOT be in an open M and will not tolerate being treated with such disrespect. Then leave it at that. You need to spend this time working on you and you need to leave her in the mess she created. Let her see that you are fine, in fact, better without her. Then go and find out how to be better without her.
Me: 48 y/o W: 47 y/o Together: > 20 yrs BD: Dec '15, then S 2nd BD: Mar '16, then I filed for D April '16: started piecing