I don't know the back story here, but I wanted to say a :iagree: to those above.
At 19, your son has the freedom of the adult and the personal responsibility of a child. He needs to be pushed in one direction or the other. Whatever rules and conditions you decide, WRITE IT DOWN. Put it in a contract, with a due date, and hold fast to it. It's too easy to make threats or conditions and forget about them or have things mis-remembered. It's much harder when those words are placed on the refrigerator door. And you have to be willing to do what it takes - if he doesn't see the counselor or finish school, are you willing to kick him out when he makes that choice?