But what about feeling empty in my marriage.
Sorry to sound harsh Ponyo and to seem as if I'm trivializing you pain but based on what you've told us here, I'd say you alone are the source of the "emptiness" that you speak of. If you think about it, the things that you are fretting about, are "first world" problems. There are millions of women around the globe who would love to have a life as "bad" as yours. They'd love to have healthy children, a stable life and a hard working man who loves them. Why not focus on what you have rather than torturing yourself by revisiting something that is over. If you do that, your problem is solved.
There is an expression "You can't go home again" and there's a pretty good chance that it might apply to your situation. After the experiences you’ve been through, (marriage, motherhood and returning to the JW's) nothing will
ever be the same as it used to be. So the “home” that you remember
doesn’t really exist anymore, because the “you” from the days that you
remember doesn’t exist anymore.
When you catch yourself going down the "what if I'd have chosen Sam instead of Leo path" switch channels and say to yourself. " thank you very much but I've already gone down this road and I've chosen to love the father of my children and appreciate what I HAVE and not daydream about what might have been". Sam is not an option to you anymore and neither is destroying your children's happy home. Stop torturing yourself by revisiting this topic and move on.