He has to go back further than where he is today. He has to go back to a child or a teenager and work forward. True going back to where he is right now may have been a happier time for him, but it's not where he was emotionally stunted. This happens with a parent or another authority figure that was in his life prior to that time. He must go back to revisit what transpired and why. He must learn to accept that he could not control what happened and that he is a good person. You may want to read this thread to have a better understanding of the "going back in time".
Some do go on to finish up their journey and others will remain lost forever, i.e., trying to live that one more time scenario. There is absolutely no way to tell which way he will go because he and God are the only ones that can determine that.
All you can do is continue on your journey and be there for your children. The focus has to remain on you for now.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
