I read your post (the whole thing) and have a question for you.
Why aren't you being honest with your W? I mean radically honest with her?
Yes, you came to bed last night, you were right in that when you said that to her....BUT you didn't initiate sex because of the tension & behaviors between the two of you....why didn't you tell her that? SHE DIDN't give you any clear signals she was interested in sex, her behavior in fact was pushing you away...and it's HER behaviors towards you in part that is also killing your desire to have sex with her.
You need to tell her these things....if she gets pissed off (and she likely will) you need to let her OWN her own reactions and feelings, don't rescue her from them or try to placate her to make things appear better....because it won't help.
Geek...tell the woman, "when you behave as you are, when you push me away....I DON'T want to have sex with you. You cannot treat me as you have been (give examples)...and expect that I'm going to want to be intimate with you." "When I'm a jerk to you...do you want to have sex with me?"
Don't hold this stuff in ("she was doing NOTHING to welcome the event that made me turn off"), get it out of your system....to her.
