If it were me, I hope I would withdraw any support, phone, car insurance anything...and anything in my name, such as car.
I would try to detach, but keep the lines of communication open, for him call you, if he wants. I would not call him. I would listen only when he calls. I would not offer help or guidance. Let him solve this himself.
Try to not blame yourself. It does not help. You love him. You acted from love and hope. You are learning.
Keep posting. Take care.
