Lil you can give worrying about your son a rest. If you can afford it, pay his rent in an ongoing way for YOU so that you aren't afraid. For your sake. No, it won't make him get a job or dump J and it could be considered enabling, but it could also be done to give YOU peace. In the end, whether you pay his rent or send him packing with nowhere to go, it is up to him to decide to be productive.
If you need him to, at a minimum, have a roof over his head, and you don't want it to be your roof, that is a solution for YOU, not him. You can never be his solution.
So if you can't function at the thought of his being homeless, and you can't live with him and if you have enough money so that it won't be a burden on you, I think it's fine to ease your mind and then let HIM fill in the rest of the blanks.
You can still withhold money for things he can find on his own, like going to food pantries and living without air conditioning in the summer if he won't work to pay his electric bill. In the winter...he can get assistance for heat. He can use flashlights for light.
Refrigerator?
He can eat peanut butter and jelly...things that don't require refrigeration.
You don't have to make it fun, but you can give him that roof for your piece of mind. Whatever it takes for you to be okay. It doesn't have to be about him anymore. Put your own needs first.
Jabber, I agree with you. But Lil matters too. You can say no to everything but the rent. Maybe tell him you'll pay the dang rent as long as he never calls his mother to ask for favors. Tell him you'll cut him off if he does bother her.
Brainstorming here....(sigh)