The singer, 29, pulled her slot at the festival at the weekend 10 minutes before she was due to take to the stage,
Festival organiser John Giddings broke the news to the audience and has since revealed that the singer will not be booked to appear again.
“She will never be booked to play the Isle of Wight again. It shows no regards for people that bought a ticket. It’s so sad that an artist would do that to their fans. She’s let them down,” he told The Mirror.
A festival spokesperson clarified to The Guardian that Giddings made his remarks after representatives for Glynne gave exhaustion as the explanation for her withdrawal.
In a tweet, the singer cited “anxiety and exhaustion” as her reasons for not being able to perform.
“I am a human being and I can’t help that my body sometimes gives up on me. I am so so gutted, sorry and upset that I couldn’t perform yesterday,” she wrote.
“I came all the way I got ready and was about to head to stage but I just couldn’t do it.”
She added: “I was incredibly weak and full of anxiety.”
And now mental health charities have spoken out in support of the star.
Jo Loughran, Director of Time to Change, the mental health anti-stigma campaign run by charities Mind and Rethink Mental Illness, told The Guardian: “Anxiety is a real and sometimes debilitating mental health problem.
"As with a physical health problem, there might be times when anxiety prevents people from working. Anyone experiencing anxiety to this degree needs support and understanding from their employer.
"We know that people still worry about disclosing their mental health problem at work so we need employers to be clear that anyone who chooses to speak out will not be treated differently, or negatively, as a result.”
Those thoughts were echoed by Marjorie Wallace, chief executive of the mental health charity SANE.
"Anxiety is a serious mental health condition that can require careful management and treatment and should not be treated lightly,” she told The Sun.
“We also hope that such stories will not discourage people from speaking openly to their employers if they are struggling with conditions like anxiety or depression.”
And Jess’ fans have also taken to social media to express their support for the singer.
Mental health isn't as simple as a physical ail, you're incredibly naive to think this and I can only imagine haven't suffered from this condition personally. She hasn't gone into detail, but she could well have had a crippling panic attack, migraine, diarrhea, or any number of..
— Robyn (@viavshop) June 18, 2019
Ignore them, ignore all of them. Anyone who’s been negative clearly doesn’t understand how anxiety works! Sometimes it just hits you and there’s nothing you can do!! You needed to do what was right for your mental and physical wellbeing!
— Mollie robinson (@Mollie_robo_134) June 17, 2019
As someone who suffers from severe anxiety, I feel for you and understand why you felt the need to cancel — in that state of mind, it’s impossible to do anything including day to day tasks let alone performing to a packed out audience! Hope you’re ok, sending love ❤️
— Daniel (@iamdanieljlacey) June 17, 2019
Jess isn’t the only celebrity to pull out of a commitment due to anxiety.
Back in 2016 Zayn Malik pulled out of a longstanding appearance at the Summertime Ball claiming it was his crippling anxiety that kept him off stage.
“My anxiety that has haunted me… has gotten the better of me,” he wrote. “I have suffered the worst anxiety of my career.”
And Adele has also previously spoken out about her own personal mental health journey and how it impacts her career and the gigs she performs.
“I have anxiety attacks, constant panicking on stage, my heart feels like it’s going to explode because I never feel like I’m going to deliver, ever,” she said.
“I will not do festivals. The thought of an audience that big frightens the life out of me. I don’t think the music would work either. It’s all too slow. I’d hate to book a festival and have a f****** anxiety attack and then not go on stage.”