Unfortunately, you are as sick as he is, you are unable to think clearly and make proper
decisions for him or you.
If you are not in therapy I wold suggest that you do so. Meeting may help, however, at this pont I am not sure that they will.
Many codependents and/or addicts just do not have a bottom, you and he both may be one of them, I do not know. I do know that your enabling is not helping him, you are a big part of the problem, he will never reach his bottom if you do not stop enabling.
Get the help you need....honestly, if you die tomorrow who is going to take over your obsession with your son? Perhaps, you should allow him the dignity to learn how to take care of himself, to become an adult...and possibly someday a responsibile one.
If I sound harsh I am sorry, however, you are out of control and as a result, so is he.