Shawn Mendes: 'The fear strangled me. I really fell down'

As a teen he wanted to be the biggest pop star in the world, but global fame came with crippling anxiety that left him unable to sing. So, three therapists and 55 self-help books' later, has he overcome his addiction to success?

Shawn Mendes had a simple ambition. He wanted to be the biggest pop star in the world. At the age of 14, he taught himself guitar from YouTube videos. At 15, he was recording six-second covers of other people's songs on the social media platform Vine. By the time Vine was discontinued three years later, he had clocked up more than half a billion views.

When he was 17, his debut album of self-penned songs (with help from seasoned professionals), Handwritten, went to No 1 in the US and his home country, Canada. So did its two successors. His first No 1 single, Stitches, has been viewed on YouTube well over 1bn times, as has Senorita, a duet with his girlfriend, Camila Cabello. His song Treat You Better is closing in on 2bn YouTube views. It really is an astonishing story.