The 19-year-old singer - who was admitted to rehab for three months in November 2010 to receive treatment for an eating disorder and self-harming - explained a ''lot of emotion'' went in to recording the ballad as it was a ''very difficult'' song to write.
She said: ''It was a very difficult song for me to record. It was a cry for help for me. And I felt very raw when I recorded it. A lot of emotion went into this song.''
Demi believes her problems stemmed from being a ''workaholic'', and she now listens to her body much more to ensure she gets plenty of sleep and eats well.
She added in an interview with the Daily Record newspaper: ''Being a workaholic might have been the problem in the first place. I never stopped, I was like the energy bunny, I was going and going and going.
''No more of that. I am ready to lead a different life now. I listen to my body now, I eat better, I get my regular sleep. It's amazing what a good night's sleep can do. You feel so much better for it in the morning.''