Rihanna nearly cancelled a concert in Ireland on Friday (25.11.11) due to stress.
The 'We Found Love' singer broke down shortly before the show in Dublin - part of her Loud Tour, which features over 100 dates - and was only talked around by a phone call to fellow singer Beyonce Knowles.
A source told The Sun newspaper: "She's just a young woman who just wants to have fun, but she was feeling pretty low.
"It's a mix of exhaustion and stress. She's been partying hard to take her mind off things, but there are days when she wakes up and doesn't even know where she is because of the travelling.
"It's no wonder she is feeling down."
Beyonce took time out in 2009 so she could spend time with her husband, rapper Jay-Z, and understands the pressures of being on a long tour and dealing with stress, as she has been performing and since she was a teenager.
The source added: "She knows Rihanna needs downtime or she'll burn out."
After her performance on Friday, Rihanna wrote online: "I'm so light-headed!"
On Thursday night (24.11.11), the singer had thrown a lavish thanksgiving feast in Ireland for her tour staff and entourage to celebrate the traditional US holiday of Thanksgiving, ordering food from a top French restaurant and celebrating in a private room of O'Donoghue's bar.
Rihanna had to cancel two shows in Sweden a month ago, as she was hospitalised with a bad case of flu. She was also thought to have been warned by doctors to curb her partying lifestyle.
Rihanna has 16 dates left on her Loud Tour, which concludes on December 22 in London.