The 51-year-old music mogul - who is thought to be upset at having to let her go from the US version of `The X Factor` and replace her with Nicole Scherzinger - is worried about their relationship and thinks the pair may never talk again.
A source said: "He was saying, `She`s had it with me. I`ve hurt her and she won`t forgive me for this.`
"He is really worried that she won`t speak to him ever again. Simonfeels guilty as hell about what has happened to Cheryl, he has admitted it was a cock-up but she won`t hear him out.
"They used to be so close. She`d text him round the clock for advice. Now she can`t bring herself to speak to him. He feelslike he`s lost a lover."
Simon made his first public appearance since her leaving the US show on the semi-final of UK TV show `Britain`s Got Talent` on 30.05.11, but Cheryl - who has worked closely with the music mogul since joining the UK version of `The X Factor` in 2008 - reportedly did not watch and instead searched for holidays on the internet.
Another source told The Sun newspaper: "Cheryl had no intention of watching Simon`s big night. It was the last thing she would be interested in.
"She still feels badly let down and seeing his face will make her more upset. Cheryl spent most of the evening checking out possible holiday destinations. She can`t wait to get as far away as possible from all this attention as possible and was eyeing up destinations in the middle of nowhere."