In an interview with the New York Times, his manager Scooter Braun revealed that Justin wanted to tour since 2014, but he left because Bieber did not have a good physical and mental health:
" I was not going to stop working, he wanted his tour, but honestly at that time felt that if he did he might die. "
Braun did not have details of what really happened to Justin, but promised that as soon as they think is the right time, and Justin feels ready, it will be totally honest with her fans.
A few days after he left his most recent album, 'Purpose', it was rumored through social networks that the singer was about to commit suicide after writing the song, which is called the title of the album material.
It is not yet known whether these rumors are true, so far Bieber fans will have to wait until Justin tell you about what really happened in those two years.