Each marital situation is different and the dynamics are different, but I know that my wife started coming back to me after about 6 years of craziness, when prayers were answered that shut doors in her life, and when I established my own personal boundaries, and stuck to them. I showed that I was working on myself and my relationship with God, my kids, etc. I was no longer focused on my wife and the marriage. As long as I chased my wife, she had control of me and the marriage. When I gave control of my marriage and life to God and pursued Him, she came back over time. It took patience and perseverance, and more importantly I was finally okay with whatever her choices were going to be, because I was content with myself and God.