It definitely doubts like there was some childhood trauma and mental illness. Do you think he would be willing to get counseling or take medications?
It might help you to get counseling for your stress level, or to attend Al Anon meetings. Many parents say those meetings help tremendously. Being disabled is stressful enough on its own. I hope things get better.
He still has time to turn this around and lead a productive life. If he waits too long, he’s going to find himself 35 without job skills and living with you.
My advice would be that it’s possible some of the restrictions you may want to put upon him he will not be able to live with, the first one being no drugs. We all want that and most of us have requested it, but it’s doubtful that he will comply. Most kids may say they will, but then they just sneak and do it anyway. You don’t need that in your home, and you don’t need to have a child who is violent and/or disrespectful living with you, particularly given your current physical state.
Wow, never coming back to earth.......he can certainly bring the drama. Removed from the home or not allowed back into the home........either way, it sounds as though you definitely made the right call.