As a former latchkey kid with no supervision, I have to say - you dropped the ball when she was young and no one was looking out for her. Addiction doesn't happen in a vacuum, and neglect is a big factor.
She has done all of this damage to herself, but saying you don't care at all is cold, to say the least. At the end one or the other of you is going to die. How do you want that to look?
You've both made mistakes. Apologize for yours - it will go a long way. Yes, you actually have to say, "I'm sorry for the mistakes I made."