Being a genius with a high IQ, does not make you mature or mean you have any common sense.
I know many adults who have high IQ's but need a lot of help getting through the day.
You sons job at this point in his life is school.
To prove this to him, you will now need to make an appointment with every one of his teachers in the classes he is failing or not making a good grade in. You, your son and each teacher need to come up with a plan to finish out this school year and decide if son needs to attend summer school, take online summer classes or in the fall to repeat these failed classes.
If this means speaking with his therapist and figuring out how to help your son get off of drugs and away from the bad influences in his life.. like his friends, then do it.. I am almost positive your son is involved with drugs and or alcohol.. It all falls into place and yes, pot is a drug.
Here in Austin, we have an alternative high school for students that do not fit into the typical high school. They can still be on a college track, but the student controls the pace they want to achieve this. Maybe your district has something similar.
What a shame he no longer can participate in the singing and dancing group. Many times being a part of a group like this can keep a kid so busy and motivated they will do whatever it takes to continue to be a part of this.
I would encourage you to have a sit down with your son and start all over on his privileges. Establish a new protocol.
His cell phone will now be limited to him only being able to call you. You can set this up with your cell phone provider. He will call you each time he is leaving to go to another spot. MOM, you will then either physically go to these places and do spot checks, or you will call the school to verify he is there, or call that friends house.. You may have to do a few times during each of these stops to make sure he has not left.
IF he is not at these locations as he says, he will not be allowed to go out unless you drive him and escort him into school and then pick him up from school.
Your son will need to figure out how to make up the homework that has been late (if the teachers will accept this). This does not mean he will get the grades, but it will mean he will know when he is assigned homework, he needs to get it done.
If he were participating in a sport or a competition based activity, he would have to maintain his grades to participate in the competitions. Not wanting to let the group and the Coach/Instructor down can be a major motivator. You may need to see if his teachers would be willing on filling out a "Friday report" that shows his current grade and any missing homework or projects.
Your son suffers from depression. This is a chemical imbalance in his brain. Using drugs can give him the sense of calm or control, but in reality it is a false moment. He should be on a good diet and probably be on an antidepressant so he can have at least a working emotional baseline.
Depression is not being weepy and laying around.. It can make a person aggressive, make them defiant and also make them totally scatterbrained.. Make sure he finds a constant solution for this so he can have a chance to experience "normality" in his emotions..
You are his mom, you are his biggest supporter emotionally, let him know this has not changed and never will, but you will not be a part of him failing because he did not do his best.. .. You know he can do better and you will be there to help, but he needs to get on top of all of this before he ends up missing out on opportunities.
There is nothing worse than the end of Senior Year when it feels like everyone is getting acceptance letters to schools and trying to decide which one to pick.. and there is the person that let it all slip away because of some poor choices.
It is not too late. Let him know this. I have seen kids that messed around and their grades were poor, they had not participated in school, but they were able to turn it around. He still has time to be in control of his future..
I am sending you strength.