02/05/2013 at 05:25 PM EST
She had never been in love before. Then, a few years ago, Kelly Clarkson
finally figured out why, she says.
"I was dating skinny jeans and I needed Wranglers," the singer, 30, tells PEOPLE in this week's cover story.
So when she fell hard
for music manager Brandon Blackstock a year ago, she knew it was something special.
Relaxing at their Nashville home together in December, Clarkson recalls, "Out of nowhere I just said, 'Thanks for being an awesome guy.' I've never been loved properly by a man, and I was just like, 'I thank you so much for that.' "
What she didn't realize was that Blackstock, 36, was about to propose
. "Not a damn clue!" she says. "If I did I would have worn something besides Uggs and a sweatshirt with no bra."
Now the couple is busy planning an "earthy" outdoor fall wedding at home – think yellow roses for Texas – while Clarkson also works on two new albums and preps for the Grammys
on Feb. 10.
"I didn't know life could be this happy," she says.