Embattled BRITNEY SPEARS can only take sooooo much!

She’s suffered an emotional breakdown after learning that her former boyfriend Justin Timberlake and his beautiful fiancee Jessica Biel had finally tied the knot.

Now those close to the emotionally fragile pop star fear she’s going to fall back into the same pattern of self-destructive behavior that landed her in the psych ward in 2008.

“Britney’s teetering on the brink again,” said a close source. “She had it in her head that she could still win Justin back and even started confiding to friends that she knew he was only threatening to marry Jessica to get her attention.

“It was the ravings of a mad woman.”

When Britney heard that Justin had followed through with his wedding plans, she “cracked,” added the source.

“She flew into a rage and started screaming, banging on a desk and throwing anything she could grab. Then she crumpled onto the floor in a heap of tears.”

Britney and Justin fell in love as Disney Mouseketeers but split in 2002 amid reports that she had cheated on the “SexyBack” hunk. And while Justin moved on to a red-hot career that included chart-topping hits and big-screen film roles, Britney’s life spiraled out of control.

In the current defamation and breach of contract lawsuit brought against Britney and her parents by her ex-manager Sam Lutfi, an attorney for the Spears family said that Britney’s breakup with Justin left her depressed and angry and led to drug use and her downward spiral.

Since her infamous meltdown, the 30-year-old has been struggling to make a comeback and is now getting mixed reviews as a judge on Simon Cowell’s “The X Factor.”

Britney has also been struggling with her love life. As The ENQUIRER recently reported, she called off her upcoming wedding plans to former agent Jason Trawick, 40, over concerns about his commitment to her.

Meanwhile, Justin, 31, and Jessica, 30, exchanged vows in front of 150 friends and family members in Southern Italy on Oct. 19. The happy couple hosted a five-day celebration at the Borgo Egnazia resort in the town of Fasano.

“Britney’s been having serious doubts about Jason and, as crazy as it sounds, she truly believed she could lure Justin back,” confided the source.

“She’s in a bad place right now.”