"2020 has brought a lot of change also to my personal life. Definitely didn't see anything coming that came," the 38-year-old singer told viewers.
"What I'm dealing with is hard because it involves more than just my heart, it involves a lot of little hearts. We have four kids and divorce is never easy," she continued. "We're both from divorced families. We know the best thing here is to protect our children and their little hearts."
Clarkson said she'll refrain from giving too many details about the divorce out of concern for the couple's kids.
"I'm usually very open and I usually talk about everything, but in this case I will talk about a little bit here and there about how (the divorce) affects me personally, but probably won't go too far into because, you know, I'm a mama bear and my kids come first," she said.
The "Stronger" singer added that she was doing "OK," and that writing music was helping her to deal with the emotional pain. "Music's always been my outlet to help me get through difficult times," she said.
Clarkson filed for divorce from Blackstock, 43, in June, citing “irreconcilable differences” and requesting joint custody of their two children, daughter River Rose, 6, and son, Remington, 4. Blackstock also has two kids, Savannah and Seth, from his previous marriage.
"You can ask anyone that's gone through divorce," she said "I don't think anyone expects it. You see yourself growing old with someone and then life has a different path, and it's so hard on everyone."
"Going through it, it's just a really difficult thing. ... I feel like everyone's 2020 is that, especially during COVID," she added "It's just a rollercoaster of emotions."