I feel your pain, Christiana. My son is also mentally ill. He also uses meth, which brings on psychosis. I'm enrolled in a "tough love" program currently, because that's what I need to do right now. I believe my son is capable of making better choices (take his meds; don't use drugs) and living companionably in our world. But I also believe we need to reopen asylums for people who can't manage or don't want to live here.
People think of asylums as bad places, but they don't have to be. For homeless people who are mentally ill, having a place to sit down, sleep, wash, use the toilet, eat, be safe and able to secure precious items--that would be a godsend. We owe it to them.
Sending blessings to B. May the angels watch over you both, and your children, and my boy, and all the people hurting in the world... :(