My mom is a utter mess, and insists that others have to take care of her. I did it for years. I believed her that she was always a victim, and she was injured, and she needed help...etc., etc. I have learned after many years that nothing that I can do will save her. She will continue down her destructive path on her own. She is also a drug addict. I have tried rescuing her, I've tried nursing her, I've tried calling the doctors, the mental health board, etc. The thing is, none of it ever helps. In reality, my mom survives very well on her own by using other people--whether or not I'm around.
I'm telling you this, because I feel that your situation is very similar. It is not your responsibility to save him. It sounds like he is not interested in saving himself, so there is nothing you can do for him. He is manipulating you. He is trying to convince you that you are responsible for his actions. In reality, he is responsible for his actions. Period.
I think it is very important for you to focus on taking care of your health and wellness. You just can't keep up this pace forever--feeling like you are responsible for everything around you.