Narcissistic Personality Disorder (NPD)

"Her natural inclination is to take the blame and assume that she is the problem. I don't know what is causing this behavior and am limited in my ability to comfort her."

Sounds to me like she married someone with Narcissistic Personality Disorder (NPD). The control issues, alone, scream NPD, particularly the sexual witholding. There's no mention about whether or not this man behaved this way prior to the marriage. If he did, she knew what she was getting into and needs to promote marital counseling for them both. If the behaviors began AFTER the marriage, she needs to get individual counseling and prepare to get OUT.

I would urge her to seek counseling to identify what's going on (or, NOT going on) in the marriage - the sexual issue is just a symptom of underlying dynamics or dysfunction. Then, I would urge her to start reading on NPD and begin taking control of her own life. The best thing that you, as a sibling, can do is to let her know that you are there to support her in her decisions, however, you cannot live her life or make her decisions for her. At some point, you may need to step back even though you want to help - some people (like myself, for instance) need to learn to take the reigns of their own lives in their hands and make changes happen for themselves.

Best wishes to you. Tweet