You have to realize there is nothing more you can do to convince someone you love to turn their life around. You simply have to say, "Look. I love you, but I cannot stand by and watch you kill yourself slowly. When you want help I'm here. Until then, goodbye." That may sound cruel, but self-preservation is paramount to helping someone else. If you're a wreck, you're useless to them, anyway. And if they refuse help, despite knowing the likely outcome, they will head down that path anyway.