I say, and with God's guidance: You should be keen on maintaining your connection with him and advising him, not cutting off from him. The true connector is the one who reaches out to those who have cut him off, not the one who is simply reached. He is your son, and your compassion for him is greater in guiding him, and this is achieved through complete communication, not by cutting off from him; therefore, there is fear of sin for those who cut off. And God knows best.