The cousin should definitely not be part of your marriage. Also, to be devil's advocate here, the way women are wired is they want sex when they feel safe, sexy, wanted, loved, cherished and valued. That doesn't sound like the situation right now. To complicate things more, you mention past trauma in your wife's life/family. That can also lead to some MAJOR intimacy issues and make sex very complicated when it's a complicated subject already! It sounds like you both could benefit from I statements so you fight fair. Maybe you can communicate with love rather than battling and trying to win or be right. So the way it works is you say , "when you do or say BLANK feel BLANK because BLANK." Also, give each other one sincere, genuine compliment each day. That works wonders. In my opinion, continue with the counseling together if you value your marriage and you may also both benefit from individual counseling as well. The cousin needs to give you two space to work on your marriage and should not live with you.