Sober alcoholic marriage, sort of

I have been sober a little over 26 years. I have been married for over 18 years. Since we got married, my wife quit going to Alanon, where I met her. She was very active in it until we had kids. We have two kids 16 (son) and daughter (11). When we first got married, we had very little sex, maybe once per month and I could live with that. Over the years I got fed up with asking my wife to have sex, she almost never initiated it. Over the years the sexual relationship is gone. I have no desire for her at all and she never indicates that she is interested in it either. In addition, since she has quit going to Alanon, her desire to control me and the kids has become almost obsessive and it has become very difficult for all of us, her behavior that is. Her contolling nature has become worse over the years. I have attempted marraige councillng several times and she went once to each and never went back and never wanted to do what the therapist suggested. I am still acitve in AA and trying to keep things together, but her behavior has become very difficult and I am getting resentful at her for being so controlling and the way she treats the kids. She plays the martyr role and when I confront her about it, she gets defensive. When I try to offer help around the house it upsets her. I do not know what to do. It seems I cannot offer help and then she goes around the house upset because no one will help her. I cannot find any information anywhere about this situation. I don't think getting an attorney is do able because I cannot afford one. Her parents have money so I would be taken to the cleaners if I filed for divorce. My life would be ruined and it is already difficult enough. I am beginning to fear for my sanity. Does anyone have any experience with this and if so, what did you do?