I don't know how to help you with him but I must say, and this is coming from someone who was basically just like your son when I was younger.

You need to stop blaming yourself, it's not your fault at all at this point. I blamed my mother for "enabling" me for a while until I finally got on my own and realized that was only ever just an excuse as nothing changed until I changed. I had free will all along and so does your son.

Now anecdotally, I was in a terrible place mentally, perhaps you should try and get an appointment with a psychiatrist/therapist? Mental illness can and will ruin your life if left unchecked and for me led to many of these same symptoms your son has.