The spectacular success of One Direction gave Liam Payne immense fame at the mere age of 16, but it also brought a number of mental health issues for the musician who resorted to isolation and heavy drinking to deal with his pain.

The "Strip That Down" singer opened up about the dark days in an appearance on Monday's episode of "The Diary of a CEO" podcast, revealing that he hit rock bottom at the time and even struggled with suicidal thoughts.

"I was worried how far my rock bottom was going to be. Where's rock bottom for me? And you would never have seen it. I'm very good at hiding it. No one would ever have seen it," the 27-year-old confessed during the episode, where he has also announced his split from fiancée Maya Henry.

When host Stephen Bartlett asked the "X Factor" winner if there were moments of "suicidal ideation" during these low moments, Payne replied, "Yeah. There is some stuff that I have definitely never, never spoken about. It was really, really, really severe. It was a problem. And it was only until I saw myself after that I was like 'Right, I need to fix myself.'"

The singer said that it was a few pictures of him on a boat looking all bloated that made him realise his problem and the need to fix it. "I call it my pills-and-booze face. My face was just like 10 times more than it is now. I just didn't like myself very much and then I made a change," he said.

Payne, along with his bandmates Harry Styles, Louis Tomlinson, Niall Horan, and Zayn Malik became the biggest boyband in the world after their group was formed on "X-Factor." The musician said their time was "wild" with constant partying that went on for several years of his life, "but it was the only way you could get the frustration out in the day."

"As a teen, the one thing you need is freedom to make choices and freedom to do stuff. We were always locked into a room at night. And then it would be car, hotel room, stage, sing, f-ed. So, it was like they pulled the dust cloth off, let us out for a minute to go 'Woohoo' then it's like 'Get back underneath here!'" Payne explained.

Payne has had a lot of changes in his personal life since "One Direction" disbanded in 2015. He also welcomed son Bear Grey Payne with ex-fiancée Cheryl Cole in 2017. However, his struggle with alcohol continued during the coronavirus lockdown in England last year.

He started drinking earlier and earlier as well as eating badly, and when someone asked about his sudden weight gain, he gave the excuse that he was doing it for a movie role. However, after seeing himself singing on TV, he decided to make a dramatic change in his lifestyle. The singer has been sober for a month now and regularly hits the gym.

Payne also spoke fondly of his former bandmate Harry Styles during the interview, recalling a "lovely phone call" the "Watermelon Sugar" hitmaker made to him the other day. He revealed: "He was checking in on me. It's almost as if some people have got a sixth sense about when you're going through something and want to check in. He's very much like that. He's a lovely, lovely boy. I love him to pieces."

One Direction
Liam Payne with his One Direction bandmates VALERIE MACON/AFP/Getty Images