@Tiredmother1 I am a tired mother too. You are in a heartbreaking situation. A lot depends on his willingness to be basically responsible, drug free, and respectful to you in your home. If you feel he is putting effort in and his outbursts are getting less, maybe there is hope. I would make a few statements about boudnaries and expectations and as an adult how long he may expect to feel the supportive environment you provide.
I have been accused of enabling, when it was not appropriate. Mums are hard shoes to fill. My son has never used drugs or alcohol. As I do believe his circumstances were out of his control and that he is putting in good effort, I have extended the safety net ... eg ... you can stay a few years if you need to ...but he pays board, and has never missed, and does odd jobs, which is trickier but we are working on it ... I believe they need to put in ... financial and chores and respect.