Wishing, you if he's over 18, could walk away at this point. I can see why parents continue to support kids who respect them, but you son doesn't respect you. I'm sure he feels far superior to you and will find someone else to scam into giving him what he needs if you cut him off. He can trash anything you give him because he knows you'll just give him another, and all he has to do is stay in junior college. He doesn't appreciate anything you are doing for him.
You must be unhappy and exhausted. You can have that grown up life of your own that you envisioned. You get to move on even if he doesn't. He doesn't actually have to have a practical job that pays a reasonable salary that's good for his temperament to survive. It would be nice, but it seems unrealistic given the type of lifestyle he is living. I'm sure you worked hard to get what was needed for your family, and like everyone else you kept some jobs that you hated because no one was handing you a free lunch. It feels to me like your idea that he will graduate school and get a great job and become a model citizen is less realistic than that you can realize that your life is your own again because he's an adult and it's time to let him make his own choices.
Good luck to you. I hope that you will start doing things for yourself. You deserve it. It might help if you talked to someone who was objective and could help you to get back to keeping your life happy and safe.
