S.F.
This may have started out as simple sadness about not fitting in at school, but it sounds to me like it has progressed to clinical depression. He is very vulnerable at this age. There is no shame in taking him to see a therapist. Go ahead and talk to the guidance counselor, but I doubt that will be enough. Teenagers, especially boys, have very little impulse control, and he may start getting angry about his loneliness. Please don't wait to get help.