I had a feeling it might be a family member Reg and I’m so very sorry your brother, his daughter, you, your parents, the rest of your family and his friends (that it sounds like he’s lost at this point). I was thinking that AlAnon might be the best path for you, your parents, and I think they have one for kids maybe to(?) If your brother would go to AA that would be wonderful, but I have a feeling he won’t. AlAnon is like AA but for family and friends. That program will let you get answers to what you, as his brother, can do to help him. 
Good luck Reg.