The is very interesting and seems helpful. Have you considered actually using these theoretical terms in your screenplay? Either through dialogue or maybe Matt reads about them? Not sure if it needs it, but your narrative is fragmented at times, and it might be difficult for an audience to follow.
This summary also reveals some things for me that I didn't catch in your 1-page synopsis. The Superhero can represent what Matt would like to be, but it can also represent what he thinks his son might want him to be. Can he live up to the role model status of an ideal father. Have you considered adding scenes with Matt's own father? Perhaps he sees his father as a successful father, and now he sees himself as a failure. Or, if not Matt's own father, then perhaps he has a friend who is a father, and Matt compares himself to this person. This person might not even be a "good" father, but his son is still alive. How does that add to Matt's frustration?
Should Matt actually blame himself? How did his son die?
Will you ever have scenes with Matt's ex-wife? It might be helpful.
One movie that is similar thematically is Manchester by the Sea. It does not contain superhero delusions, but it is about a father who blames himself for his kids' deaths.
This summary also reveals some things for me that I didn't catch in your 1-page synopsis. The Superhero can represent what Matt would like to be, but it can also represent what he thinks his son might want him to be. Can he live up to the role model status of an ideal father. Have you considered adding scenes with Matt's own father? Perhaps he sees his father as a successful father, and now he sees himself as a failure. Or, if not Matt's own father, then perhaps he has a friend who is a father, and Matt compares himself to this person. This person might not even be a "good" father, but his son is still alive. How does that add to Matt's frustration?
Should Matt actually blame himself? How did his son die?
Will you ever have scenes with Matt's ex-wife? It might be helpful.
One movie that is similar thematically is Manchester by the Sea. It does not contain superhero delusions, but it is about a father who blames himself for his kids' deaths.