I don't have a teenager yet (just a three year old) but I've been reading a good book which seems to be relevant for whichever age. Its called 'how to talk to kids so they will listen and listen so kids will talk' by Adele Faber; Elaine Mazlish. Its available on Amazon. Its terrific. The empathy and the problem solving ideas seem pretty good - especially the problem solving for that age I'd imagine.
Its ultimately up to your son what he wants to do, as he's getting older and more and more independent. But, you can help him to figure that out, make the choices available to him and give him some support with whatever he's finding difficult. Punishing him is probably not helping, and may be making it worse. It seems time to try some different and more empathic approaches to work out what's going on for him. You can offer incentives or 'goodies', trips, outings etc he can work towards if he makes little bits of progress. He may need some extra help with his homework etc - do you take the time to work with him on school work everyday ? I'd say that's probably what he needs (more attention, support and praise) more than anything. His self-esteem may be really low, and if none of those ideas help, it might be worth trying therapy. Also, has he been tested for learning disabilities such as dyslexia? Good luck, I know its not easy!