The 26-year-old singer auditioned for 'The X Factor' and was put into eventual-winning band Little Mix with Jesy Nelson, Jade Thirlwall and Leigh-Anne Pinnock in 2011, and she felt as soon as she "made it", her old pals faded away.
She said: "I've lost a lot of friends. Which is s**t. I feel like as soon as I made it in the group, I lost everybody
"A bit of betrayal, a bit of bitchiness."
The 'Black Magic' hitmaker admitted it is harder to maintain friendships because of her career and thinks those who drifted away didn't really understand her situation.
She told Cosmopolitan magazine: "It's harder when you're in the [music] industry, because you don't have the time any more and a lot of people don't understand that.
"It works both ways - I can't make all the effort and have this mad career. "The people who are in my life now are the ones who matter ... It's quality, not quantity."
The blonde beauty admitted she used to be far more confident until she was under the microscope of the spotlight.
She said: "When we were younger we were so confident.
"Then when we got flung into the industry we began to get self-conscious and started criticising ourselves because other people were doing it
"Every time I got papped, my teeth would look buckled at the front. I hated them. I got braces."
But now, she's doesn't worry as much.
She added: "I'm just more confident ... We've come out of the other side and we're like, 'Who gives a s**t what other people think?'"
And Perrie couldn't be happier when she's at home with her boyfriend Alex Oxlade-Chamberlain and the other people that matter to her.
She said: "When I'm around my friends and family in my house and I've got my boyfriend there I'm the happiest person alive.
"There is nothing better than having people around you who make you feel special, make you feel calm, make you feel normal."