Avi is backed by every well know Rav and Chasidus. He only meets the Parents and not with the kids.
Nuchem Rosenberg has his own agenda and I will not elaborate. He will not nor can he help you all he will do is try to find out who the molester is and go after him publicly.
Your son needs to see a therapist and you and your husband need to learn to show the utmost support for him.
I am not a politics person so what ever reb doniel refers to is not for you be concerned with.
Your Son now is # 1