Kelly Clarkson nearly broke down during her performance on "American Idol" last month. In her final appearance on the show that made her famous, she had judges Keith Urban and Jennifer Lopez in tears as well as everyone watching at home and in the audience.

Clarkson performed her single "Piece by Piece" and her struggle to complete the song left her feeling "embarrassed." With her husband Brandon Blackstock and daughter River Rose waiting in the wings, the performance proved an emotional rollercoaster for the 32-year-old pregnant singer.

"I came off in tears for a difference reason because I was so embarrassed," she said on "The Ellen DeGeneres Show." "I was like this is my final thing on 'Idol' and I could not hold it together. I was almost losing it the entire song. I was proud of myself for making it as far as I did."

"Piece by Piece" addresses Clarkson's relationship with her father, who divorced her mother at a young age, and was written following a conversation she had with her sister about their family. In the song, she also promises that she and her husband will never abandon their daughter and unborn son.

"And [Blackstock] was there. My little girl was there. My little boy is turning circles in my stomach. It was nostalgic. It was the last time I'm ever going to be on 'Idol' and it's ending. I was screwed from the get go," the "Breakaway" singer said.

"Piece by Piece" comes from Clarkson's seventh studio album of the same name, released in February 2015. It was her first studio album to feature all original music since her 2011 album, "Stronger," and followed the release of her 2013 Christmas album, "Wrapped in Red," in 2013. The new album debuted at No. 1 on the Billboard 200 chart.

Lopez also spoke of Clarkson's very emotional performance on "Late Night with Seth Meyers" on Wednesday and revealed that she didn't realize Urban was "falling apart" next to her until she watched the episode playback later that night.

"I go, 'Oh my God. I'm an idiot,'" Lopez said and motioned that she didn't even rub his back to comfort him. "Not one time did I look at him and notice he was sobbing. The grown man next to me was sobbing. I had no idea."