The 44-year-old singer, who separated from the 'America's Got Talent' host over the summer after six years of marriage, is reportedly suffering from severe insomnia because she's a "mess."
A source close to the '#Beautiful' hitmaker, who has three-year-old twins Monroe and Moroccan with Nick, is frustrated that she no longer has the happy family unit she wants and "can't sleep."
The couple have yet to file for divorce and friends believe Mariah is eager for a reconciliation.
The insider told Us Weekly magazine that she isn't ready to "give up the idea of a happy family."
The 'Hero' hitmaker broke down in tears while performing at the Beacon Theatre in New York City last week.
Nick recently insisted he and the blonde beauty would always be family despite reports their split was getting contentious.
Asked about their plans for Christmas, he said: "Always focus on family. We'll forever be family.
"At the same time, we're there for our children, making them the No. 1 priority and understanding they're loved and can have an amazing holiday."