i am in the same boat and have been for at least 10 yrs out of my upcoming 18 yr marriage. i am 45, she is 43. two boys 11 and 14. i also work 4-5 jobs to keep things afloat, help around with the house, and parental responsibilities(i don't know if these things have anything to do with anything). i'm just saying that i participate fully as a husband/father, and try to go above and beyond my duties to make her happy and less stressful.
i also have stopped trying to have sex with my wife, stopped talking about sex, stopped trying to be romantic, erotic, assertive, passive, etc. nothing works. i too have shut down all communications, and am just "being."
as long as i do not bring up anything that pertains to sex, or anything that deals with making our marriage more romantic, she is happy.
she has no sex drive, knows she doesn't have any desire for sex, says she isn't going to do anything about it, and if i don't like it, "there's the door."
we've gone to a therapist, and once we started talking about her, she refused to go anymore, because she said that there was nothing wrong with her, and she is the normal one, that everybody she knows is just like her. she also got her hormones checked and they are fine.
everything is for the kids, and her career. whenever there is any down time it's filled with either relaxing on the couch, or just going to bed.
and the irony is is that if you were to see us together, you would say,"wow! they seem to have it all together!" because she calls me "honey," and holds my hand, or puts her hand in my backpocket. but once behind closed bedroom doors, it's all about trying to get a full 8 hrs. sleep.
i need an answer and help too, because no one can stay in a marriage where one has a deep desire for the other, but knows the other feels the complete opposite. i have done everything possible (argued; tried to change any bad personality traits she said i have; love letters/poems; flowers; being assertive physically/being passive physically; gone to a therapist myself; etc.).
it's like living with an ex-girlfriend: you're always trying to get her back, but she wants nothing to do with you, and only wants to be your friend.
