Singer-actress Demi Lovato was taking drugs while promoting her sobriety in 2012.
Lovato confessed in her new documentary "Simply Complicated".
Lovato, 25, went to rehab in 2010 to seek treatment for her dependence on alcohol and drugs, and to get therapy for an eating disorder and self-harming.
Of her relapse in 2012, Lovato recalled: "I wasn't working my program, I wasn't ready to get sober. I was sneaking (cocaine) on planes, I was sneaking it in bathrooms, sneaking it throughout the night… I went on a bender of like, two months where I was using daily.
She added: "There was one night when I used a bunch of coke and I popped a few Xanax bars, and I began to choke a little bit. My heart started racing, and I thought to myself, ‘Oh my God, I might be overdosing right now'."