Keith Urban on how Nicole Kidman stood by him early in their marriage: 'She chose love'

Keith Urban is sharing how Nicole Kidman stood by him during the early days of their marriage.

While honoring his wife during the "49th AFI Life Achievement Award: A Tribute to Nicole Kidman," which aired on June 17, but was filmed in April, Urban opened up about the time he went to rehab shortly after they wed due to past "addictions."

"We got married in June 2006 and barely four months into our marriage, my addictions that I had done really nothing about blew our marriage to smithereens and I went into the Betty Ford center for three months," Urban began. "Four months into a marriage, and I'm in rehab for three months with no idea what was going to happen to us."

"If you want to see what love in action really looks like, give that a whirl," he continued. "Nic pushed through every negative voice — I'm sure even some of her own — and she chose love. And here we are tonight 18 years later."

The couple, who share teen daughters Sunday Rose and Faith Margaret, met in January 2005 during an event where Urban got her phone number on a "tiny piece of paper" that he said he carried "in my pocket for well over a week."

"I was scared," the "Somebody Like You" singer recalled. "I was nervous to call her and as prone as I might have been at the time to all sorts of delusional thinking, even I couldn't stretch that to think that this extraordinary woman would ever see anything in a guy like me."

Urban eventually found the courage to call Kidman, and he said that when he did, it felt like they had "known each other our whole lives."

"It turned out that this mystic creature was really just a wide-eyed, vivacious giddy girl from the Sydney suburbs and despite being born in Honolulu, she was utterly Aussie through and through," he said.

"The thing about Nic -- she loves life," Urban added. "I've actually never met anyone who has such a passion for being alive. She knows the importance of expressing feelings as well. I wasn't raised like this at all so our girls are very lucky to be learning from you, baby. I'm learning too."

Kidman was also honored by many of her former co-stars, colleagues and friends, including Mike Meyers, Meryl Streep, Zac Efron, Naomi Watts, Joey King and more.

The AFI Life Achievement award "celebrates an individual whose career in motion pictures or television has greatly contributed to the enrichment of American culture," according to the American Film Institute.

Past recipients include Julie Andrews, Denzel Washington, George Clooney and Diane Keaton.

While the evening was to celebrate Kidman's body of work so far, Urban used it as a chance to also celebrate his love for her.

"Next year will be 20 years since I've been madly in love with you," he said. "Congratulations baby girl, I love you."

Along with their two daughters, Kidman also shares daughter Bella and son Connor with ex-husband Tom Cruise.