Keith Urban’s Introverted Nature ‘Wrecked His Personal Life’ With Nicole Kidman (Exclusive)

Keith Urban has turned into a major loner in recent years, and a source tells National Enquirer that he’s pushing old friends away and worrying everyone by turning into a grumpy shadow of his former self.

“The key to Keith’s success over the years is the same thing that ruined his marriage,” the source says. “He is willing to lock himself in a room, isolate for hours or days at a time, and he won’t come out until he has a great song or at the very least, an exciting guitar solo. It’s the only way he can get any work done.”

According to the source, Urban, 57, has “given everything he has to becoming a better musician, deep into middle age.”

“Right now it looks like that’s wrecked his personal life,” the source adds, referring to his split from Nicole Kidman.

Even before their split, the source says Kidman — who filed for divorce on September 30 — struggled with his withdrawn demeanor.

“Even in their happiest years, Keith’s loner streak and introversion tested Nicole’s patience,” the source explains. “She worked around it and figured out a path through it.”

“Now that they’ve called it quits, Keith is more alone than ever because everybody who knew them as a couple knew about these quirks in his personality.”

The source claims Urban is channeling that isolation into music: “Everything is about self-pity for him and the only way he plows past that is composing music.”

“Even when he and Nicole were being cheered for their loving red carpet appearances, Keith never put a lot of stock in his Hollywood acquaintances, and he’s not taking a lot of those with him as the marriage ends.”

“Nicole is a bridge-builder and a connector in a way that Keith has never been,” the source continues. “She’s taking the friends with her in this split, and that’s no surprise because she’s so charismatic and successful.”

“People already totally understand Keith has a massive fan base, still, and he doesn’t need red carpet back-pats to keep pushing,” the source concludes. “As sad as it is, he’s going to go it alone for this next chapter, and he’s going to do it far away from Los Angeles, just how he likes it.”