The good thing is that you can start right where you are with your son. You can tell him you have always tried your best and, hopefully, he will understand you always had his well-being at heart and you love him to distraction. And, yes, some of these children are fragile and have issues with negative influences, but teaching them resilience, as you have tried to do, is actually a good thing. As I said, start from where you are, but remember - his choices are his choices; you are not responsible for those. All you can do is express your love and support however you can.