James Arthur pulled out of his Teenage Cancer Trust show due to a pre-existing knee injury which caused him "crippling anxiety".
The ‘Say You Won’t Let Go’ hitmaker was devastated when he was forced to cancel his planned performance for the charity at London’s Royal Albert Hall in March, just hours before he was due on stage, due to suffering from poor mental health.
And now he has explained how not being able to run and exercise after sustaining the injury made him feel "trapped".
He told The Sun newspaper’s Bizarre column: "There was a lot of things going on at the time and I’d actually injured myself, I’m still dealing with a knee injury.
"Running was one of the really helpful ways to combat the anxiety and I wasn’t able to do that so I felt a little bit trapped at the time. Simple stuff like playing football, staying healthy and mindfulness helps."
The 31-year-old star – who shot to fame on ‘The X Factor’ – is still being treated and has to have injections in his knee.
He added: "It’s a thing I did a few years ago which I made considerably worse so I needed injections in my knees to reboot it. "I hope this last treatment I had will fix it."
Despite not playing the show, James donated £1,000 to a terminally ill fan who is supported by the charity.
The ‘Empty Space’ hitmaker sent the money via a GoFundMe page set up for Jade Davis, on which she listed the 10 things she’d most like to do in her life, including meeting James.
Jade has Type 1 Chiari Malformation, which pushes the lower part of the brain into the spinal canal and means she cannot work, cook, or shower on her own.
Following his donation, Jade took to Twitter to post a screenshot of her GoFundMe page showing his generosity, and wrote: "What an amazing man @JamesArthur23 (sic)"
James told his fans he had been "badly" affected by his anxiety in the days leading up to the concert.
On Twitter, he wrote: "I’m deeply sorry to announce that I’m going to have to pull out of the Teenage Cancer Trust performance tonight.
"I have been feeling crippled by anxiety and poor mental health over the past few days and it’s badly affecting me. I simply cannot perform tonight."
James then apologised to the Teenage Cancer Trust for dropping out of the show, and declared he is "looking to get help" from a professional for his mental health.
He added: "I would like to profoundly apologise to the amazing Teenage Cancer Trust team, to all that have bought tickets to see me and to the boys from Take That, it was a dream to be able to perform alongside them but devastatingly I cannot perform this evening.
"I promise I will make it up to you and I’m looking to get help for this x (sic)"