My fourteen year old son also has "anger management" as he calls it (I call it a lack of anger management...lol). He chose to live with me when he was 11 and refused to go back to California to be with his dad. At that time he would have "anger outbursts" once to twice a week. He would break things and punch walls. He even put a fist through one of my kitchen windows. Now he has them only about once every three to four months (thank goodness).
What I did was talk a lot with him about his anger when he wasn't angry. I asked him about what was happening in his mind, and how his body felt when he got into that "anger" and it took over his mind and body. He said when he goes into that rage, he reaches a point where he can't stop it. And at that point, if I push him or say anything to aggrevate him further it escalates into something violent. We decided that if he starts to feel himself "lose control" he needs to tell me that he is "getting really mad." At that point I give him a "cooling off period" and he stays in his room doing whatever (laying in bed, playing a video game, etc.). After the cooling off period (which can last anywhere from 5 minutes to 2 hours) we talk about what happened calmly.
This happened Friday, as a matter of fact. He got angry with a teacher at school. Evidently, he had gotten the window in the classroom open, got some snow and put it on a girl's head. The teacher gave him a 20 minute detention where he had to pick up all the paper left on the floor. He called me (I teach at the high school) and told me he was pretty mad he had to stay, and that he wasn't going to. I told him to "bite the bullet" (a phrase I use a lot with him), take responsibility, and get it over with. He did, then, decide to stay. For his detention the teacher had him pick up paper because she couldn't have him pick up the snow, but thought he needed to pick up something. He didn't think it was fair that he had to pick up any paper because he hadn't put it there, but the teacher didn't know how "NOT FAIR" he thought it was. He picked up all the bigger pieces of paper in the first ten minutes then he sat down. She told him to pick up the smaller pieces for the last ten minutes. He was now extremely sure that it wasn't fair and he was angry so he started out the door. She didn't realize that he had been angry in the first place, so she thought it was no big deal and she told him if he left he would have double the time picking up paper on Monday after school. He "blew" at her right then and there! I am not exactly sure what he said, but when I talked with her she was definately shocked by his behavior. I went home from work and tried to talk him into going back to school and finish the detention and pick up the paper. He was too angry, telling me now he was probably going to get in trouble all the time at school (just like last year when he had the record for the number of times in the timeout room). He said that no one understood and that he wasn't like anybody else. Other people are "normal," not like him who has "anger management." I told my son that it seemed to me that he still needed time to cool off, but that he and I would need to go into school early Monday morning to talk with the teacher and work this problem out. He made me a promise (pinky swear), that he would go then. I then went to the school and explained to the teacher that I had given him 30 minutes to cool off but it wasn't happening right now. She said she had NEVER seen anything like that from him and that it was fine to let him cool off and come in Monday morning. (I just told her she was lucky it wasn't last year when this happened on a regular basis).
Since Friday I have taken many opportunities to show my son that life is not fair. Like when he doesn't hang up his coat. It's not fair I have to pick it up because I didn't put it there. And when he wanted batteries for his video game controller. It wasn't fair he should get batteries and I don't give batteries to everyone in the house. And wash his dishes...well, you get the idea. I frequently remind him about our early Monday morning with the teacher. Because he is fully prepared he is fine with going now, and even having to pick up papers.
I also think what has helped with him is setting up clear expectations. Sometimes he will pull his fist back to punch something, but he knows what will happen if he does. (I told him I would call the police if he destroys anything in our home again). So now I just tell him, "punching that wall would be a choice, but you know what the consequences will be if that is the choice you make." Then I just walk away. He hasn't punched anything since we discussed what the consequences would be (thank goodness, because I would just hate to have to call the police, but I would, I have to because I said I would). Because there are no surprises he now has enough information to make good choices.
I don't know if this helps, but I think the best thing I have done, is talk with him about his anger when he's not angry and let him know what he can expect if he does get so angry that he does destroy something. I also go up and lay with him in his bed when he is going to sleep or we sit on the couch together after everyone else has gone to bed, and we talk about all sorts of things. Problems at school: low test grades, kids he doesn't like, girls he does. Things I'd like him to do at home. We have lots of communication and I think that helps.
I know if I found marijuanna in my son's room on the inside I would be furious and worried, but I wouldn't let him know. I would take it away and tell him we would talk about it later. (I would need a cooling off time). Then I would talk calmly about it and ask him what was going on that made him decide to buy it. I would ask a lot of questions and then tell him the facts: it's against the law and what the consequences are if he is arrested, how it affects his developing body and brain, etc. I would let him know that it is ultimately his choice whether or not to smoke himself stupid, but he is not allowed to have it in my house because if he does I will have to call the police. I would also tell him that I know he is intelligent and knows it isn't good for him and a poor choice. And that I believe enough in him to do the right thing.
I know things will get better with your son. And I know how difficult it is for you now. But hang in there, it is so worth it when they get smarter...lol.