We'll have to agree to disagree then. She was clean of drugs and had given up drinking apart from the binge that killed her... I do think she was on the 'up' - at least from where she was anyway.
Ignoring the little matter of the alcohol and that horrible performance a few days before she died of course.
Just swapping one addiction for another. If Amy hadn't have died that week it would have been the next week or the next or a month later or a month after that.
Plus the damage she had already caused to herself was probably irreparable - listen to Whitney's voice for example.