When Gayle King asked Kevin on "CBS Mornings" Thursday how he was holding up head-wise and heart-wise post-divorce, he didn’t mince words: "That's a crushing moment. It's powerful, it hurt."

Kevin added he had no choice but to move forward and couldn't wilt like a daisy -- especially 'cause he had to keep a special eye on his kids who were looking up to him.

You'll recall ... Christine and Kevin finalized their divorce in Feb, wrapping up one of Hollywood's messiest splits. While the settlement details stayed under wraps, we do know a judge upheld their contentious prenup.

The exes asked for joint custody of their 3 kids -- and, a court ruled Baumgartner should receive a hefty $63k in child support from the former "Yellowstone" actor.

Our doc "TMZ Investigates: Kevin Costner's Divorce War" dives into the nitty gritty of the divorce saga further -- and is available on Hulu.

Christine has since moved on ... confirming her new romance with Kevin's former friend Josh Connor with a hand-in-hand stroll last month.