Your son certainly sounds very discouraged and unhappy, which can happen to any teen and gifted teens are not immune, especially if they do not feel like they fit in or if they are not able to use their gifts. I am actually wondering if he is experiencing depression.
When you meet on Friday, will there be a counselor there? I think it might make sense to address this as a counseling/mental health issue rather than a discipline/motivation issue. If there is no counselor there on Friday, I would arrange a meeting with a school counselor or other mental health professional to discuss what is going on, especially the fact that he seems to no longer enjoy the things he used to enjoy--that is an indication that it may be more than just "underachieving". Even if this is over-reacting I would definitely take the better safe than sorry approach in a situation like this.
Good luck!
