The 50-year-old actress - whose estranged husband Ashton Kutcher filed for divorce on Friday (21.12.12) more than one year after their split in November 2011, after which she checked into rehab for an alleged eating disorder and substance abuse issues - is reportedly on a downward spiral since her three daughters Rumer, 24, Scout, 21, and Tallulah, 18, cut contact with her because of her hard partying.
A source told RadarOnline.com: "The girls want Demi to pull herself together, act her age and stop carrying on like some teenage party girl. But Demi just refuses to give up the lifestyle that once made her happy, even though it now just amplifies her loneliness.
"She`s determined to find young love again and is at a loss as to why she is still single. On top of having no love life, her daughters have once again turned their backs on her - she just feels so alone, and that feeling is made all the worse as Christmas approaches."
The brunette beauty - who was dumped by her 26-year-old toyboy lover Vito Schnabel earlier this month - is said to be particularly dreading spending the festive season because her ex-husbands Bruce Willis and Ashton Kutcher have both moved on.
Bruce recently welcomed a new daughter Mabel with his wife Emma, while Ashton has been romancing his former `That 70s Show` co-star Mila Kunis for the past nine months.
The insider said: "Bruce will be spending Christmas with his wife and their new baby, then obviously there`s the whole Ashton Mila situation.
"Demi feels so alone in the world. Her mom and step dad are both dead... and although she has three stepsiblings - she hasn`t spoken to them in 30 years! And her half brother James is in jail for 10 years for assaulting his girlfriend so there is no one for her to spend the holidays with. It`s going to be another sad and lonely time for Demi.
"Demi`s friends are worried she will be so down over the holidays that she may relapse, and they no longer know what to do to help her."