First, you have my sympathy and admiration. I fell into the insane trap of trying to do the same things over and over again and being surprised that the outcome was always the same. It took over a year of therapy before I even recognized my need to stop and the damage my enabling was causing.

I learned to say no to my son and his addiction. No money, no lawyers, no job references, no warm bed or hot meal reapyaed with theft, eventually I even refused to visit him in jail until he agreed to go into a drug rehab. I also learned to say no to the employers, robbery victims, disapproving neighbors, and anyone else who got in the way of my no.
We were lucky. He was able to get off drugs and to some degree on with his life. He could just have easily died in a crack house or beaten to death by one of "friends".

PM me if you want to talk. And get the support of a professional. You may not "need" it but a strong, supportive advocate will make your life a lot easier.