She recently got engaged to music manager boyfriend Brandon Blackstock, and their love has been a main reason for the singer's happiness.
"I didn't know life could be this happy," she tells this week's PEOPLE, where she appears on the cover.
Kelly is excitedly planning an "earthy outdoor all wedding," complete with yellow roses, the mag reports.
Recalling how Blackstock popped the question, Kelly says it happened when they were hanging out at their Nashville home together.
"Out of nowhere I just said, 'Thanks for being an awesome guy,'" she says. "I've never been loved properly by a man, and I was just like, 'I thank you so much for that.'"
Then, much to Kelly's surprise, Blackstock proposed.
"[I had] not a damn clue!" she recalls to the mag. "If I did I would have worn something besides Uggs and a sweatshirt with no bra."
Kelly is sure to be all smiles while rocking her gorgeous ring at this Sunday's, Feb. 10, Grammy Awards, where her number one hit, "Stronger (What Doesn't Kill You)," is nominated for record of the year and best pop solo performance.
"I knew from the moment I heard it that it was going to be huge," she tells Associated Press of the song. "I've heard everything from `I got out of an abusive relationship' to `I'm surviving cancer' ... and I think everyone in the world needs that type of song -- something that makes you feel empowered."
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