My brother is drinking and taking drugs. I feel so helpless?

My brother is 29 and an alcoholic who also does cocaine and takes other pills. He had been in jail for 4 yrs, which helped him get sober, clear his head, and basically grow up. He's been out since July and just found out he has been binge drinking and snorting cocaine again. I feel so helpless. He's going to either kill someone else or himself from a DUI, overdose, or go back to jail. I feel like there is no happy ending to this. I really feel the only reason he is alive right now is because he had to go to jail. I feel like my only option is to level with him when he is sober and convince him to go to rehab. He is so talented, has a job he loves, friends, a loving family, and pretty much a lot going for him, except he is an addict. I guess I am searching for advice on how to get through this, and how I can sleep at night without worrying about him.