This much be tough not only for your son but also for rest of your family seeing your son in this position. It's not an uncommon situation, I have worked with several teenage boys to help them with stress / lack of focus, troubles at school and had great success.
I originally trained as a nurse, have Level 3 in counselling and recently trained as a kinesiology practitioner. Kinesiology looks at the whole person and through muscle testing, something kids love and find very empowering, can quickly get to route of the problem. So we can then help them manage this through various easy techniques they can use in their everyday life.
This can work along-side other therapies or as a stand-alone. The sessions are one on one kids also love (parent in the room if they wish), the client lies on a massage couch, has muscle testing, some massage whilst talking. The fact it’s physical as well as talking kids seem to embrace and open up far more.
I’d be delighted to speak to you further and of course have the opportunity to help your son.
Look forward to hearing from you.
All the best