Hi there,
Firstly you need to back away, preferably with love. He may not think it’s with love and kindness at the time when you stop bailing him out, but in the long run it’s the only solution.
My husband was the addict, I can’t begin to think how hard it must be if it’s your child. It’s easier in a way to leave a spouse but when it’s your child, the thoughts of “what might happen to him” if you don’t help, I imagine must be overwhelming. In some ways though it’s helping to keep him stuck.
I recommend that you seek help, try Al anon they have been a life saver for me. They are mainly for families of alcoholics but drugs/gambling whatever it’s all addiction, so the principles are the same. They show you how to live again, how to regain some sanity, because I know how hard and emotionally draining it is.