The question to go to a Rav or not to go to a Rav needs to be looked at from another angle. You do not go to a Rav for counseling most of the time. While some are very good at it others are not. You go for 2 reasons. 1 is to get a recommendation for a good counselor. Finding the right therapist is a must because you need someone who will understand your hashafa and background and not do too much damage. Too many non frum or non Jewish therapists see this as a not issue and will not take it seriously.
My friend and her husband are still together. Most people who go through this do not make it. What healing will require is total honesty. No, the wife should not become the mashgiach and check up on him. What she has to do is make a culture of safety for him to come to her when he slips. And he does need to go to therapy to deal with these issues. Many times there are underlying issues like compulsive lying and a need to make yourself feel more powerful. It can work and they can have a happy marriage again. But only if the husband is totally honest and willing to work at it