CANNES WATCH: Nicole Kidman talks her loneliest experience, and her princely husband

CANNES, France – Nicole Kidman has never had to make the choice that Grace Kelly did, quitting acting to begin another life as Princess of Monaco. But she’s rarely found equilibrium in her career and personal life.

“When I won the Oscar, I went home and I didn’t have (love) in my life,” said Kidman, who won best actress for “The Hours” in 2003, two years after she and Tom Cruise were divorced. “That was the most intensely lonely experience in my life.”

Kidman stars as Kelly in “Grace of Monaco,” which premiered Wednesday as the opener of the Cannes Film Festival. In it, she plays Kelly following her marriage to Prince Rainier of Monaco (Tim Roth) as she adjusts to royal life and severs ties with Hollywood.

“Strangely for me, the greatest highs have coincided with the greatest lows,” said Kidman. “So (during) my professional highs a lot of times I’ve had personal lows and they’ve collided. That’s always aggravated me that it’s gone that way. I’m hoping one day I can have a professional high and a personal high.”

Kidman said she drew from her own life to empathize with Kelly, although they differ greatly in husbands.

“I am married to a prince,” said Kidman, who wed Keith Urban in 2006. “A country prince.”

— Jake Coyle, AP Film Writer (Twitter: http://twitter.com/jake_coyle