SAD LOSS! Inside AGT star Nightbirde’s sad last days as she weighed just 85 pounds in ‘brutal’ cancer battle before death at 31

AMERICA'S Got Talent singer Nightbirde opened up about her "brutal" cancer battle just weeks before she passed away at the age of 31.

The artist, whose real name was Jane Marczewski, detailed her experience battling the disease on social media, even revealing that she got down to just 85 pounds at one point.

The entertainer, who passed away on Sunday, became an overnight sensation last year after her incredible AGT audition, with a video of her performance racking up a staggering 30 million views on YouTube.

Nightbirde shocked fans when she announced her exit from the show's finals on Instagram due to her deteriorating health.

Since then, she'd kept fans updated on her battle with photos and videos on social media.

Her final post on her IG feed was a smiling selfie from early January, where she noted how hard her life had been but tried to remain positive.

"Honestly, things have been pretty brutal," she wrote in the caption. "But this is a photo of myself from last week where I felt pretty, and alive, and awake, and human, and real."

She added: "I needed that. We're all a little lost and it's alright.