J-Lo broke down in tears just thinking about her lost loves   She\'s maintained a dignified poise ever since her break-up with husband Mark Anthony, but tonight Jennifer Lopez broke down in front of a packed auditorium as she sang about love . The 42-year-old was shimmering through her headline performance at the Mohegan Sun Arena\'s 15th anniversary celebration when she started sobbing and had to leave the stage. Jennifer had just performed a raw, unembellished rendition of \"I You Had My Love” when she told the audience that the 1999 track was “the first song I wrote about love.” The emotionally overwrought superstar then shocked the crowd by beseeching: “What is love?”  Tellingly in the song that Lopez penned before all this happened, she ends her entreaty to a lover with the line: “I have to know the truth, If I spend my life with you.”  But the mother-of-two had set herself up for the cavalcade of painful feelings by having dancers recreate her important relationships while she sang. A P. Diddy double danced with the female dancer wearing a copy of her infamous slit-down-to-the navel Versace gown, while a ringer for her ex-husband Cris Judd danced with a paired down Lopez-a-like in jeans. Another doppelganger was wearing the mint green gown she wore to the Oscars with fiance Ben Affleck as she twirled with a square-jawed replica of The Town star. But the most dazzling pairing came from the twosome reliving Lopez and Marc Anthony\'s American Idol performance from May, only weeks before they announced the end of their marriage. At the end of the song she started sobbing and had to take a few moments to keep it together, according to an onlooker. “She held it together for one song but then ran offstage crying. She only sang a few more songs and she was obviously out of it. Everyone was so sad for her. It was really dramatic.”