It is very difficult to help someone in denial. Even Alcoholics Anonymous recognises that the road to healing and recovery begins when the person admits to having a problem.
And when you try to gently get them to face reality they get angry and lash out at you. The standard accusation is that you cannot understand because you are not in the same situation and that you would have responded in like manner if it had happened to you.
And so they remain stuck in a world of "what might have been" instead of embracing a new season in life.
How sad can it be?