It is very likely that reaching bottom can be a long process...especially when they are so comfortable.
Littlemama.....I have also had that fear and still do about my kids dead or worse. However, they can still die at any point even if they are living with me or not. It is the hardest thing you can do is to let go. However, there is NO way to protect them from themselves.
It took me awhile to figure this out. I guess I was getting sick myself and tired of everything being about them.
You will know when the time comes...keep getting some support in healthy places!