That song..... Addiction sucks. I cannot offer advice on relationships. My own story is testament to that. There is so much information and support atr SR. Also there is Al-anon. You have identified this is effecting you, your son and your wife. Firstly make sure of the health and safety of you and your son. I do not mean your partner should be isolated, but she has to heal for herself. Dynamics of where your son goes, that requires much thought and input- perhaps from a relationships counsellor?
My thoughts, support and prayers for you and your family. Keep posting.