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While Demi Moore is undergoing treatment at an undisclosed location, more details of the night she was rushed to the hospital have surfaced, and the latest issue of People magazine reports on a life that seemed to be spiraling out of control.

Kate Coyne, People's assistant managing editor, shared some of the details this morning on "Good Morning America."

"Demi was so frail and so gaunt that some of the paramedics who arrived actually thought that she was a cancer patient who was in the final stages of treatment," Coyne told "GMA"'s Paula Faris.

Moore was rushed to the hospital Monday night after a 911 call was placed from her home saying she had "smoked something" and was "shaking," "semi-conscious" and "burning up."  While some have speculated Moore abused the drug "spice," others have suggested she inhaled nitrous oxide, a popular party drug.

According to People, Moore has been struggling for years and was "tormented by insecurities about her body and age."

People also reported that she used prescription drugs to "curb her appetite," and that these insecurities became more of an issue after her split with "Two and a Half Men" star Ashton Kutcher.  Moore and Kutcher faced a very public split after multiple allegations surfaced of Kutcher cheating.

Moore told Harper's Bazaar magazine, " 'What scares me is that I'm going to ultimately find out at the end of my life that I'm really not lovable, that I'm not worthy of being loved. That there's something fundamentally wrong with me."

She also told Harper's Bazaar she struggled with her body image and acceptance of herself.

"The weight loss that Demi has had is indicative of a much bigger problem - problems involving drugs, reckless behavior and, really, a refusal to eat," Coyne said. "She has been so obsessed with staying young and, to her, staying young means staying thin."

Days before she went to the hospital, the 49-year-old Moore was reported partying with her daughter, Rumer Willis, 23, and her 20-year-old friends.

Moore is no stranger to erratic behavior.   In 2010, her wild dancing at a Snoop Dogg concert caused embarrassment to her former husband, Kutcher.

Bruce Willis, Moore's ex-husband and father of her children, "ask[ed] her to get help … but she just wouldn't listen," People reported. 

"Demi is absolutely mortified and feels absolutely humiliated that all of these problems have come to light," Coyne said. "She is a very private person and these sorts of struggles are things that she never wanted the world to know about."

ABC News' Randy Kreider, Paula Faris and Amanda Keegan contributed to this report.