I`m sorry you cannot afford him a psychiatrist or better psychologies who could talk to him because he cannot prescribe medications. Your son sounds like he needs help. And it is good he is ready to get it.
I think he could wait a bit until you earn some money, but nothing will change until he gets help. How much time would be enough for you to do that?
I have no idea how it goes in USA, but here we have social services... They do all kind of things to help problematic families connected to addiction, violence, counseling, and having no money.
But I guess that doesn`t help you because your medical system s*cks, as I`ve heard.