Mel, big huge
to you for being the strong mother you need to be. I wish my MIL could be as strong as you. My BIL is a drunk, manipulative abuser and hasn't held a job in years. He takes in women to support him and bail him out. He uses his mother to no end but she's an enabler and doesn't see her fault. I have told her so many times that we will NOT support him when she dies. She thinks he'll be fine. He compares himself to Jim in disabilities as if he's jealous.
Anyway, enough about that. My advice and take it or leave it is keep doing what your doing. My heart aches for you because I can feel your pain in all this. You have let go but your heart hasn't or you wouldn't be here posting.
He's an adult and you have to let him fall. I personally think all these organizations are enabling him as well. If he keeps getting bailed out he wont hit rock bottom.