Clarkson and Blackstock, a music manager, were married in October 2013 and share two children, daughter River Rose, 5, and son Remington Alexander, 3. The couple had also been raising Blackstock's two children from a previous marriage, daughter Savannah, 18, and son Seth, 14.
Clarkson said she's been relying on loved ones to help her through the difficult split.
“I’ve been talking to friends that have been through divorce," she said. "I don’t know how people go through that without having some kind of outlet because it is the worst thing ever for everyone involved."
Clarkson has also been pouring her emotions into songs on her upcoming album, which she plans to release next year.
"This'll probably be the most personal one I've ever released," the singer said. "And the whole record is basically every emotion you experience from the beginning of a relationship to the end of what it is now or where it is now, and it's been very therapeutic for me."
She continued, “It’s very honest. There’s one that my kids sing in the car. I’m going through mixes, and I’m just, like, ‘This is weird.’ Like, it’s your relationship. I’ve never written about my life to where my kids are singing along."
Watch Clarkson's full interview on Sunday TODAY here.