"I think this is the best birthday gift I could ever give myself is just to once again be honest with myself and break down the things that I've struggled with for so long," she told Katie Couric in an exclusive interview airing on "All Access Nashville with Katie Couric" on Friday.
Rumor had it that Rimes, 30, sought treatment for everything from an eating disorder to an addiction. But in her interview with Couric, the teen country music phenom -turned-crossover pop star said she wanted to set the record straight.
"People look at you and go, why are you struggling? You know...no one can quite understand why you hurt so badly," she said tearfully.
Rimes traced her motivation to enter a 30-day voluntary treatment program back to her childhood. The Mississippi native made history by winning a Grammy at age 14, but said that early success also brought with it early sacrifices.
"I wasn't a kid. It's as simple as that and so complicated at the same time. (You) like to see your kid be a kid, you know. And I didn't get any of those things. So I feel like everything was kind of ripped from me and given to me and handed to me on a plate at the same time," she said.
Rimes said that the treatment program was specifically geared toward helping her cope with stress and anxiety. Rimes said that the most important thing she learned while there was "be comfortable with me outside of what I can do."
"Everything worked around my voice. It was the way that I lived my life," she said. "If that was taken away, I want to know who I am outside of that."
But Rimes still loves singing and she said the songs on her latest album "Spitfire" -- slated for release this spring -- are all about communication. The album, Rimes said, was a way to release anger that she had kept bottled up for too long.
"The album's called 'Spitfire,' because I literally feel like at times, I'm spitting fire," she said.
But at least one of her new songs is about contrition, not anger. In "What Have I Done," Rimes sings dolefully of how she hurt her now ex-husband, Dean Sheremet. Rimes divorced Sheremet after starting an extra-marital affair with actor Eddie Cibrian, who was also married at the time.
"I've carried a lot of guilt for a long time, I think," Rimes said. Sheremet, she said, heard the song just after she wrote it and "probably knew what it was about before I did."
Another new song, "Borrowed," is about the actual affair with Cibrian, whom she married last year.
"I carried the title ("Borrowed") around with me for about eight months, because I was so unsure of how to write it, without offending anyone, because I had to be so honest in order to write it," Rimes said.
Rimes said she struggled with the criticism and the media firestorm that followed her romance with Cibrian before coming to terms with the fallout.
“It was very, very difficult. I wouldn't wish it on anyone…and especially in the public eye to go through all of it,” she said. “I made my choices and I'm living with them. And I also have learned from them and I've talked about this so much. But I know that…I'm not the only person that goes through this. There's so many that do.”
Today, Rimes is not only a wife but also the step-mother to Cibrian's two sons from his previous marriage. Rimes said she would also like to have children of her own some day and that she and Cibirian discuss the subject all the time.
"But for now," she added, "I'm totally, totally happy with having (Cibrian's children) running around. And I love them to death."
Watch more with LeAnn Rimes on "All Access Nashville with Katie Couric," a special edition of "20/20," Friday at 9 p.m. ET.
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