You may not like this idea but neighbor had to do it with her grandson( don't ask why she had him LOOONNNGGG story)
He could have freinds over only for a couple hors, and if he needed any thing she went with him . Drove him to school , (mostly embarassed him ) It was hard on her but it got him through a tough spot. Later on when he moved out he got in to trouble but by then he wasn't her responsiblity.
She informed him that when she felt she could trust him shed back off slowly and he could then have a little more freedom and Resposablity.