Hi Gerette64. I'm new here, too. From the perspective of a teenager who uses, which I once was...just being more strict and taking priveleges away did nothing but fuel my desire for drugs and alcohol.
I would never have admitted it then, but I wish my parents had taken a more proactive stance regarding my addiction. I'm not blaming them at all. Believe me, I know that I made my own choices.
My parents were extremely strict with me. They grounded me, lectured me, took away my car, watched me like a hawk, checked my eyes, purse, pockets each time I walked into the door...and still...I partied like crazy. When a person wants to do drugs, they will find a way around every obstacle.
Your son needs professional help, so that he can begin to at least admit that there just may be a problem here. Only when he sees that, can he begin to heal. I'll keep you both in my thoughts and prayers.