John Calipari's Daughter 'Not Okay' After Arkansas' Stressful Tourney Win

Arkansas head coach John Calipari's daughter was on an emotional rollercoaster during the Razorbacks' first-round upset in the NCAA tournament ... and even after the win was secured, she admitted she was "not okay."

Down three points with three minutes to go, cameras caught Megan struggling to keep her eyes on the court as her dad's team tried to claw its way back on top.

Hunching over in her seat, her mom, Ellen, was doing what any good mother would do ... comforting her and assuring her that everything would be okay.

Luckily for the Cal clan, it did work out for the Hogs ... beating No. 7-ranked Kansas in a thriller. After the game, she posted on her Instagram that while she appreciated everyone's concern, she was still dealing with the effects of the game.

It won't get any easier for Megan and Arkansas -- the team is set to take on Rick Pitino and No. 2-ranked St. John's in the next round.

The two legends have gone head-to-head 23 times as college coaches ... with the 66-year-old Calipari leading the matchup with a 13-10 record.