The Atomic Kitten singer was left devastated on Saturday (February 15) when she found out the former Love Island host had been found dead at her flat in London.
Kerry said she felt like she should've done more to "help" when she reached out to her last year after she was charged with assaulting her boyfriend Lewis Burton.
Speaking to Sky News, Kerry said: "This is what really upsets me because I know how it feels, to feel that low.
"And when someone reaches out to you like that and I felt like I've not helped her enough.
"Because of idiotic people on social media trying to get more followers I don't think they understand the impact it has on somebody's mental health.
"It's so so wrong on so many levels."
The day after her death, Kerry uploaded the private messages she exchanged with Caroline in December after the former The Xtra Factor host asked her how she dealt with cruel remarks from the campaign organisation Fathers 4 Justice.
"Her death cannot be in vain."
Former singer @KerryKatona7 says she thinks abuse on social media contributed to the death of Caroline Flack, and urges users to be more aware of the impact their comments can have on people's mental health.
— Sky News (@SkyNews) February 17, 2020
Kerry, 39, explained: "Regarding our messages to one another, I don't know if I did the right thing in putting those up on social media but I do feel like her death cannot be in vain.
"I had to show people what it's really like for people like myself and Caroline in this industry when you make a mistake and you're not even allowed to try and fix that mistake in privacy.
"I know how it feels when you lose all your contracts and everyone turns against you.
"Me, myself, I'm a mother to five amazing children and Caroline is a human being who is allowed to make mistakes.
"We are allowed to make mistakes, we learn from our mistakes but the fact that she wasn't even allowed to learn from his whole situation angers me so much."
At the weekend, Caroline's family said in a statement: "We can confirm that our Caroline passed away today on the 15th February. We would ask that the press respect the privacy of the family at this difficult time."
Last night, Love Island paid tribute to its former host as it returned to screens.
The moving segment was put together by Caroline's friend and the show's narrator Iain Stirling as well as the crew.
As the camera panned over beautiful sea and sunshine scenery, an emotional Iain said: "
If you or someone you know is struggling, call Samaritans free on 116 123 or email email@example.com and someone will get back to you.
Leave us a comment on our Facebook page @EntertainmentDailyFix and let us know your thoughts on this story.