Law of Least Resistance

I have a relationship question in relation to the Law of Least Effort. My husband has a sex addiction and as a result he has repeatedly been unfaithful and has asked for a divorce twice while under the sway of his addiction. He has contacted the last woman in moments of stress and weakness. In both instances I talked him out of leaving me, and he has said that he does not love this woman and does not want to leave me, that his addiction makes him believe these things. He is currently in a 12 step program, is seeing a therapist, and is trying to make amends and overcome his addiction. We have a child together. If we did not have a child I don’t think I would have the strength to try and make it work. It has taken everything in my being to look past what he has done and try to see it objectively as a disease even though the consequences have devastated me personally. My question is this; should I have followed the Law of Least Effort and let him leave even though I felt it was a mistake? Am I resisting the direction that life is trying to lead me? Are we to completely surrender to all events, whether good or bad?