Perrie Edwards "could barely leave the house" last year due to agoraphobia.
The former Little Mix singer suffers from crippling anxiety in everyday life and feels more comfortable when she is performing on stage.
Perrie told the Daily Telegraph newspaper: "When I'm on stage being a pop star I'm fully in my element: brave and empowered.
"But as soon as I'm back home behind closed doors, that's when the anxiety kicks in and I'm just me again."
She added: "I can't help but catastrophise about the everyday things that ought to be easy, like getting in my car and driving to London.
"At the end of last year my agoraphobia got so bad I could barely leave the house."
Perrie has embarked on a solo career since Little Mix went on hiatus in 2022 and admits that she felt a renewed sense of pressure because she was "starting from scratch".
The 32-year-old star said: "I was in the studio thinking: 'I need to write a hit! I need to write a hit today!'
"The music industry is so competitive and I felt I was starting from scratch. It's a pressure cooker in which you're constantly being compared to everybody else and I just couldn't find a sound that I believed in..."
Perrie is engaged to footballer Alex Oxlade-Chamberlain, having been in a relationship with the former England international since 2016, but admits that she was sceptical about dating him at first.
The Forget About Us hitmaker - who was previously engaged to former One Direction singer Zayn Malik - said: "I never planned on dating a footballer.
"I thought after my past, all the s*** I went through, that I would end up with somebody normal, somebody who worked in an office, or a bricklayer. Not somebody from my industry. I was raised to think footballers were wrong'uns, that they'll cheat on you. I knew people would have no sympathy for me."
Perrie - who has son Axel, three, with Oxlade-Chamberlain - recalled how her family had concerns about her partner when they first got together.
She said: "(Until) they met him and said: 'Oh! Now we feel awful.' He's the sweetest, most funny and genuine person."
Perrie's former Little Mix bandmate Jade Thirlwall has been outspoken on political and cultural matters since going solo but the Tears singer has little interest in wading into current affairs.
She said: "The best thing is for women to have a choice. If you want to be political on stage, be political! If you want to keep away from that s*** and focus on other things then do that!"
