Reports claim that after K-Fed, who is said to be dating playboy babe Nicole Narain, snubbed her offer, the singer called a suicide help line.
"Britney's bouncing off the walls with rage and has been calling Kev day and night to check he's not with Nicole," News of the World quoted a source as saying.
"She's desperately jealous and wants to keep Kevin's attention on her. She wants him back. She thinks by getting Kevin back he'll drop the custody battle -but that's not going to happen,' the source added.
A distraught Spears, who has been ordered to take psychological tests, is also contemplating fleeing to Cuba with her two sons, a source revealed.
"She's crying all the time. It's not the first time she's been suicidal," the source said.
"She's terrified of losing her sons. There are no extradition laws in Cuba, so she thinks it's her only hope," the source added.