LeAnn Rimes sat down for an exclusive interview with Katie Couric. (Ron Tom/ABC)

Fresh off a month spent in a voluntary rehabilitation program, LeAnn Rimes says that now, at age 30, she's starting over.

"I feel like I am starting over even though I've had all these years behind me. How many people get to (start) over again in this day and age?" Rimes told Katie Couric in an exclusive interview airing later this week on "Katie" and "All Access Nashville," a special edition of "20/20?

Rimes, who hit country stardom when she was a young teen and later became a crossover pop star, entered the program to cope with anxiety and stress. Her trip to rehab prompted headlines, but it wasn't the first time she gained media attention for something other than her career; her 2011 marriage to actor Eddie Cibrian - the couple met when they were both married to other people - made her a target for the tabloids.

"People look at you and go why are you struggling? …No one can quite understand why you hurt so badly," she told Couric.

Rimes' new single, "What Have I Done," will be released this December.

Watch more with LeAnn Rimes on " Katie" on Thursday and "All Access Nashville with Katie Couric," a special edition of "20/20," Friday at 9 p.m. ET.