Malik was set to perform at the Capital Summertime Ball in London on Saturday before he backed out. After his cancellation, he took to Twitter with an explanation.
"To all those people who have been waiting to see me perform…I flew into the UK last night to appear in my home country in front of my family, friends, and most importantly my UK fans," he wrote.
The 23-year-old singer explained the extent of his struggles with anxiety and its effect on him.
"Unfortunately, my anxiety that has haunted me throughout the last few months around live performances has gotten the better of me…with the magnitude of the event, I have suffered the worst anxiety of my career."
He then gave his loyal fans a promise that he will make it up to them eventually.
"I cannot apologize enough but I want to be honest with everyone who has patiently waited to see me. I promise I will do my best to make this up to everybody I've let down today."
He also said that he hopes fellow anxiety sufferers will understand what he's going through, and hopes "those who don't can empathize with my situation."
Malik had recently broken up with model Gigi Hadid, who stared alongside him in his music video for 'Pillow Talk'.