Realistically a marriage isn’t some thing you can preserve by act of will. It’s not like maintaining a car or keeping up payments on a mortgage. Inside that legal definition are two real live human beings and unless there’s an adequate connection between them, the piece of paper they signed at the registry office is utterly meaningless. I’ve seen far too many men and women remain in dead relationships merely because they thought there was an obligation upon them to live up to some nonsensical Disneyesque fantasy of how things “should” be. Glad you got out, eventually. Some don’t.