Jesy spoke to Cosmopolitan about her exit in December, where she revealed she reached "breaking point" while filming the Sweet Melody music after having a panic attack on set.
She explained she missed one of the scenes in the music video because of the panic attack and revealed how she tried to prepare for the video shoot. "I just panicked," she said. "I went on this extreme diet, with bloody shakes, and tried to eat as little as possible.
"On the day of the Sweet Melody video I had a panic attack on set because I didn't look how I wanted to look and I found it so hard to just be happy and enjoy myself.
"There's a scene in Sweet Melody I'm not in, because that's when I had a panic attack and broke down."
Jesy has been outspoken about her struggles with body image as well as being compared negatively to her three former bandmates, most notably in the BBC Three documentary Odd One Out.
Fans on Twitter to praised the singer for being unfiltered about her experiences and praised her for being brave.
"Shedding tears of joy with Jesy Nelson's interview. I love her sooo much. She must be protected at all costs," one fan tweeted.
A third said: "I just woke up and crying for Jesy Nelson. It's a mix of happy and sad tears. [She's] finally free and truly happy."
"I just read Jesy's interview and I'm in tears," a fourth fan penned. "I am just so happy for her and so happy that she feels loved, she felt our love during that time [in] December. I love her so much."
If you have been affected by anything in this article, please contact the Samaritans on their 24 hour hotline on 116 123, or follow this link for further information.