Hello again everyone. After a few months away from mumsnet, I am back with more worry and need for advice...
The last year or so has been very difficult with my DS 14 (15 in a few weeks). The worst being cannabis smoking, binge drinking, vandalism when drunk, not coming home at weekend nights, two charges (one for vandalism and one for possession of cannabis), smashing up his room and school refusal...
I asked for help as it was all getting out of hand and we worked closely with school, children's services, police and GP. School were patient and understanding, children's services worker was supportive but conveyed the seriousness of the situation to my son (being removed from my care if not able to follow house rules) and the effect of criminal charges. Police were helpful in some ways but not in others. And GP adviced DS to accept referral to CAMHS to work on underlying issues which have bothered him since he was a toddler (saying he hates himself and wants to die at age 2. Attempted self harm at age 4).
My son did/does not want to talk to anyone about how he feels. He wants to deal with it himself. Him and his friends talk a lot about these things and they support each other. And he talks to me.
In the last few weeks things have improved considerably. He has been home on time at weekends, not been so drunk...he has a girlfriend who he seems to really like, and he has just seen his dad again after a year of refusing all contact. He seems a whole lot more responsible, and is showing that he is willing to make better choices for himself and for his family (his younger siblings 13 &11, and me).
However now that things are better, I feel I can start dealing with issues again. He is drinking way too much. Him and his friends drink almost every weekend...and if they aren't drinking, they'll likely to have smoked cannabis instead... last night he came home worse for wear (having been drinking). We had just spoken about him going out on New Year's Eve and he said he would make sure he didn't drink too much, that he would be home on time but that it would be nice to be able to stay out a bit later since it was New Years. He'd made sure not go to any parties over Christmas, as he was going to go out on NYE.
I feel so worried for him as they are binge drinking so often! I also feel ashamed about him being out drunk! How can I stop him smoking weed and drinking to excess. I know he knows what the right thing to do is, but he still ends up making bad choices.
Because of his mental health issues (undiagnosed) punitive discipline has become a thing of the past. Being supportive of his positive choices and putting the responsibility on to him has made a world of difference. But I feel like I'm just letting him do whatever...
Also I feel terrified that he'll try other drugs than cannabis. I've heard kids in his year having tried ecstasy, acid and speed. In fact he's told me some people he knows are taking it...he has often expressed a disgust of drug use (not cannabis) but I feel he is just to close to it.
I want to ground him etc for drinking too much/smoking cannabis but am scared to reopen old wounds, provoke conflicts and end up him feeling let down by me and deciding to just not care and try other drugs too 
At the moment he says he's staying away from drugs for me...
I'm keeping my 13 year old inside to keep him away from this 'street kid' culture which my oldest seems to 'thrive' in.
Any advice from parents with hard to handle kids?!