Spears assistant spills the beans!

For three of the most turbulent months of the pop star's life, Kalie Machado was a constant by Britney Spears' side.
Plucked from a hairdresser's assistant gig in December 2006 to serve as Spears' personal assistant, Machado, 23, soon found herself a featured player in Brit's daily soap opera, a drinking companion and shoulder to cry on.
Now living back in Northern California, Machado tells Us all the heartbreaking details of Brit's breakup with Kevin Federline, and how Spears, 25, even desperately tried to win him back.
"She wanted so badly to have the father of her babies. When Britney thought about Kevin not wanting her, she would bawl," Machado tells Us. "She would look at Sean and Jayden and say, 'Where's your daddy? I need help. Where's your daddy?'"
And Sean Preston, 2, and Jayden James, 1, were with Spears when she and Federline had their final fight, something Machado says Spears felt she was tricked into. After following him to New York with their sons, "She stood up for herself, and it kind of backfired," Machado recalls. "That was what [Federline] wanted."
Unable to move on, Spears hung her wedding dress in the bedroom of her Malibu home. She also kept framed photographs of she and K-Fed all over the house. "She would ask, 'Why did he do this to me?'" Machado tells Us, adding: "It just made her crazy and depressed."
Machado's conclusion? "She needs mental help," she says.
For more revelations from Britney's ex-assistant, including insights on the pop star's alleged addiction problems, pick up the new issue of Us Weekly