I Am a Recovering Co-dependent Forum & Chat Board | Need some advice about my alcohol/drug using brother

My brother is a binge drinker, he is also bi-polar and gay and lacking any coping devices for past tragedies, including the loss of our two brothers (one died 10 years ago at age 35 when he was hit on his bike by a drunk driver, and the other died two years ago at age 54 from a brain hemorage, he was also an alcoholic and drug user) the loss of his long time partner from divorce, just to name a few. I have been trying to help him for years, but the ol' adage you can lead a horse to water....is very true. He recently had another alcohol/med combo collapse and went to emergency. My parents are old and tired and can't take the burden and fear of losing another child. I am holding everything up, to help my brother and my parents, but feel that we are all stuck in this never-ending cycle of dysfunction, codependency, and patterned behavior that has proven not to effect any change at all. Like most things it is all very complicated, but that is the gist. Looking for some advice on trying something new. I am a caretaker by nature and family role assignment and am becoming tired of the whole thing, but cannot abandon my family either. Help!!!