The boy sounds anxious and I am guessing that you are a relative. Given the brief history you described his anxiety may be related to his relationship with his mother/parents. Since it sounds like his mother has not been receptive to feedback nor willing to acknowledge that there is a problem, I suggest you contact his school and talk to a counselor or social worker. You do not need to go into detail, schools are kind of public places, but let them know you are concerned and request that someone touch base with him. Maybe if he has someone at school that he feels comfortable talking to, he will reach out himself.
Thanks Luann! I think that's helpful!