You were having an emotional affair and you regret not breaking up his family for your own pleasure? you regret not having his kids grow up with a dad in their house and loving their mother? you have lived 25 years in a fantasy of your own making and continue to fantasize about what could have been?
Simply because you two didn't actually have sex doesn't mean that your relationship wasn't completely inappropriate in normal circumstances much less for a jw.
I would be of the opinion that you need therapy to live out what days you have left in joy and learn how to let go of this fantasy you have in your head. Pining away for years and years for what may or may not have been reality is not healthy. You also need help to navigate the whole jw thing as well and learn how to leave it behind as well. It is a toxic cult. Please find a counselor to help you through this.