I think you'll feel better if you lay it out for him, though, before you remove yourself from the situation. Give him one more sit-down, explain it like you would to anyone else, ask him if he has any questions for you, and then be done. You can also promise to be there for advice and questions if that would make you feel better. I don't think it's not tough love anymore if you simply treat him like you would any other adult, and most adults would answer questions and give advice if asked.
Honestly, though, at this point I'm unsure as to how you could keep him from falling flat on his face. Arrears? No job? Failed the bar (probably twice)? It might be out of your hands at this point.
I feel you, though. One of my brothers has tendencies in this direction, and it's enormously frustrating. My solution is to treat him like an adult as much as possible.