The 63-year-old music mogul welcomed his son Eric with partner Lauren Silverman in 2014, and marked a turning point for the TV judge, whose life was consumed by his demanding career.
At the time, he was locked in near-constant ratings battles both in the UK and abroad. In the UK in particular, X Factor was consistently pitted against BBC's Strictly Come Dancing in the weekend primetime ratings, with Strictly edging ahead before X Factor was finally shelved in 2019.
"Before Eric, my life was 99 per cent work — I was obsessed with it," he told The Sun. "I got to that point where everything was about, ‘If you’re not rating against this then you’re a failure’ and I stopped enjoying what I was doing and I was miserable the whole time."
"I was obsessed with beating the competition," he added. "I took it to a ridiculous level and I would get really down about that stuff, to the point I was depressed."
Cowell added without Eric, "God knows what would have happened" as it forced him to change his priorities after becoming extremely unhappy.
Now, he's looking more positive, and insists he "isn't the same man he was 10 years ago".
Currently, there are no official plans for X Factor's return, with the series quietly being dropped from the long-standing Autumn weekend line-up in 2019.
Britain's Got Talent will return to our screens next year, with Cowell due to reunite with a judges panel completed by Amanda Holden, Alesha Dixon and David Walliams.
Cowell is now turning his attention to a new project, a talent-search initiative based on TikTok.
The new project, StemDrop, will work by seeing producer Max Martin write a new pop song and invite aspiring singers to upload their own version on social media.
This will be his first major new work project since an e-bike accident in August 2020, where Cowell broke his back while testing out his new £10,000 machine in the courtyard of his home in Malibu, California.
He needed extensive surgery to get a metal rod placed in his back, and left him with long-standing nerve damage.
WATCH: Simon Cowell teams up with TikTok for new talent-discovery programme StemDrop!