Have you looked into other possible causes like Impulse Control Disorder of Bipolar Disorder? Forgive me if you answered that in the article.
Hang in there. While you feel like giving up (any normal person would, it’s understandable) I bet your son needs your consistent love right now more than ever. He might be equally scared by his behavior, even if he doesn’t show it. Don’t be afraid to fight for him and the answers he needs. It sounds like there are underlying issues and not him simply choosing destructive behavior.