Joe Jonas is down in the dumps after being kicked to the curb without warning by 10,000 BC cutie Camilla Belle.

INFPhoto.com

Joe reportedly is heartbroken overthe abrupt end to a romance that began after he met Camilla, 22, on the set of the band’s “Love Bug” music video last summer.

Friends are concerned that the 20-year-old pop star is headed for a downward spiral after a teary-eyed Joe become overcome with emotion as he performed “Much Better” and “Turn Around” in Detroit on the heels of the young couple’s split last month.

“Joe seems ready to crack,” insiders dish in the August 17 issue of The National Enquirer. “He’s either acting like a blubbering lovelorn fool or an out-of-it zombie. His friends and family are worried sick.”

Despite being spotted out for dinner with friend Brenda Song earlier this week, Joe is described by those closet to him as “total withdrawn.”

“Camilla really put the zap on Joe, and he still has a lot of crying to do before he’s over her.”