....Hard to say. It is possible that the SSM situation is a result of someone just not having much of a sex drive. If you accept the premise that the cause is something in the relationship itself, then it is always good to work those issues out, obviously. But many times the very difference between a wife's needs and that of the husbands causes some of the issues that ultimately pushes the couple apart. In other words, it is essential to be able to differentiate between the cause and the effect, and that is not always transparent.
....My hunch is that based on your description of her, she may have used anger issues as a disguise to escape from sex and that her agenda (either consciously or unconsciously) was to take sex out of your marriage.
....My personal opinion is that abstaining from sex without mutual consent is cheating just as much as having sex outside the marriage without telling someone is cheating.
....I don't think that you need consent if someone refuses to have sex. And, I don't think that the person with no or low desire needs to want to have an outside relationship in order for you to have one.
...If you now have a relationship that you are happy with, then you have obviously made the right choice. Are you having regular sex now? Or are you resigned to the fate of having infrequent or no sex for peace in the house?
An interesting book on women and a declining libido is the book Still Sexy after All these Years. It is an interview of thousands of women across all ethnic, economic backgrounds in the US. Yes, for some women their libido does decline, for others it doesn't need to or they can find sensuality and intimacy in other ways as they mature.
For me, my wife & I did have an active sex drive when we first married, it just declined. Part of it was she withdrew emotionally from the marriage when she felt hurt. I then withdrew to work on my career to provide more for her and my children and to get praise from coworkers for my skill at work. The lack of emotional support at home drove me to the office where I got emotional support. That caused my wife to withdraw even further emotionally from me and reinforced her anger. We were in a downward spiral for a long time, until I reached my breaking point.
Affairs, would have just complicated the healing process and possible prevented the reconciliation that happened in therapy. I found that touch or physcial communication was a very powerful tool in rebuilding our relationship.
I am very happy with our current relationship. Yes we have been having sex multiple times a week; regularly for about a year. Our relationship is very strong. I honestly didn't expect to be still married to my wife by now, when we started sex therapy and marriage counseling.
I work at trying to make my wife feel loved by providing multiple acts of devotion and quality time each day. I go out of my way to do things for her and talk to her about what happened with her day and what is going to happen that is important to her later in the week. Which is what she needs to feel loved.
In return she has worked at making me feel loved.
>43 years of marriage--My wife and I are now closer than we have been in decades. I believe that my SSM is over.