Standswithcourage,
I think you must be one of the most guilt-ridden Moms I have ever read on this board.
Sending big hugs and I big dose of compassion to you!
However, I see this from another perspective. Everything you do to "help" your difficult child, isn't for HIM, it's for YOU. I sense this desperate need to avoid any kind of anxiety, guilt, and loss of control over him. In other words, as long as you are doing "something" to try and "help" him, you don't have to experience that wrenching feeling of being out of control.
I see all of this as being just as much about you, as it is about him.
Honestly, I do not know what it is like to be in your shoes. However, I watched both of my younger sibs (girl and boy) struggle with addiction. They both lived in some pretty horrible conditions, and did participated in some very risky behavior. I can't even imagine the agony it was for my Mother. Both were in their 30s before they decided enough was enough. My younger brother lived on the streets, with an occasional handout from friends, for years. He was also in and out of jail.
Also, they BOTH lived in rural farming communities and managed to handle things themselves. Everyone else had pretty much threw their hands up in frustration years ago. No rides and no place to crash. They had to figure it out on their own. However, once they started pulling themselves up, and earning people's trust, they received a helping hand on occasion.
I only help those that help themselves. Period. I figure why should invest more of my energy in their lives than THEY do??
Your difficult child may very well dig himself a very deep hole. It's his hole to climb out of. I feel for your easy child. The PCs really take it on the chin in these types of situations.
As for doctors saying that they need to stay with you? Whatever! If I had listen to Son's doctor, who thought so much of what I was doing was "unnecessary" I never would have gained an understanding of what I was dealing with. Just because it comes from an MD, doesn't mean it's correct. Offer to have difficult child go live with HIM.
Keep standing with courage. It's time, though, to allow difficult child to stand now, too.