Kelly Stafford Rips 'Insecure Men' After Backup QB Backlash

Kelly Stafford just seemingly took a huge swipe at some of her biggest critics ... appearing to blast them as "insecure men" -- while praising her NFL star husband, Matthew Stafford , in the process.

Kelly's been in the crosshairs of many haters this week ... after she confessed on the "Off the Vine" podcast that she dated one of Stafford's backups while at the Univ. of Georgia in order to make him jealous.

People flocked to her social media pages with mean remarks -- and after apologizing to former Bulldogs signal-caller Joe Cox for unintentionally getting him wrapped up in the drama ... she took to IG Thursday afternoon to apparently fire away at the trolls.

On a photo of her and Stafford at Wednesday night's Chris Stapleton concert in Los Angeles, she wrote, "Realizing how many insecure men there are out there.. so grateful I married the complete opposite."

"Loved last night #joyofmylife," she added.

Kelly turned off the comments on the post -- a pretty clear indication she's tired of reading all of the hate.

She has seemed remorseful, though, over the way the dating story blew up ... saying to Cox in a different IG post earlier this week, "You had ZERO involvement in what I spoke about."

The Cox family, meanwhile, has not yet commented on the saga ... and for his part, neither has Matthew.