I'm so sorry dear Klara. It's not your fault and there's nothing you can do. My close friend has a son who has followed much the same path as your daughter. Numerous rehabs, a beautiful wife and daughter and he can't get clean. He is in prison now and his mother went to see him for the first time in 2 years. He hung up the phone qnd wouldn't talk to her. Heartbreaking. She says she's at peace now and if he leaves this earth she is ready.