Nicole Scherzinger's life as a pop star was "really scary".

The singer started out as a member of girl group Eden Crush before joining the Pussycat Dolls, but Nicole has admitted life in the spotlight was hard for young women because there were very few conversations about mental health issues and she was very "hard" on herself.

She told PEOPLE: "I think a lot of people in the industry battle with this feeling of it never being enough. You have this insatiable hunger within you that it's just like, it never feels like enough.

"We want that validation. We want that acceptance, and we want to be seen. I was very hard on myself ...

"A lot of things have changed in the past 20 years. People are just more aware and talk about mental health. We didn't talk about those things back in the day.

"And I grew up in an extremely religious family and had a very sheltered life. So even though I was in Eden's Crush and touring around the world at 22, I felt more like a 16-year-old."

She went on to add: "Being a pop star and being thrust out there to the world when you're still trying to figure out who you are and your sound and what you like and trying to be comfortable growing into a woman into your own skin. Yeah, it was really scary."

Nicole's time with the Pussycat Dolls ended in 2009 and she went on to launch a solo career, work on reality shows such as 'The X Factor' and she's now reinvented herself as a stage star with a critically-acclaimed role in 'Sunset Boulevard' in London's West End and on Broadway.

The singer has admitted she's happier than ever after her career took her back to her theatre roots.

She added to PEOPLE: "I have worked many, many years to build up to this moment, and it's changed my life. I've never been more happy, I think, because I always had so much inside of me that I felt like people didn't see or understand. It just feels good now to be able to share that with the world."