Justin Bieber said in a candid Instagram post Sunday that he isolated himself and turned to "heavy drugs" at 19 while struggling to cope with his rapid rise to fame.

The 25-year-old pop star has become increasingly open about his personal life in recent years as he has rebounded from a string of missteps - including a 2014 DUI arrest - that led to concerns about his career. Last year, he shocked fans (and pop culture writers) when he took to Instagram to confirm his engagement to model Hailey Baldwin, whom he married two months later. On Sunday, Bieber referenced their marriage as "the best season of my life."

He put their union in stark contrast to the relationships he "abused" as he grappled with the dark side of fame. "I Became resentful, disrespectful to women, and angry," he wrote. "I became distant to everyone who loved me, and i was hiding behind, a shell of a person that I had become."

Bieber skyrocketed to fame at 13 when a little-known talent manager named Scooter Braun stumbled across YouTube videos of the baby-faced Ontario native crooning R&B hits. He certainly isn't the first child star to struggle with fame or sudden wealth - a theme to which Bieber alluded in his post.

"Have u noticed the statistics of child stars and the outcome of their life?" he asked. "There is an insane amount of pressure and responsibility put on a child who's brain, emotions, frontal lobes (decision making) aren't developed yet."

Still, Bieber faced a unique hurdle as part of an early generation of celebrities who grew up in the social media era. That has made the singer and his peers (including his famous, social-media-wary ex, Selena Gomez) more accessible to fans - and criticism.

But social media has also allowed celebrities to confront everything from rumors to harsh truths on their own terms. Bieber's post prompted messages of support from several fellow celebrities, including singer Sean Kingston, actor-model Patrick Schwarzenegger, reality star Khloe Kardashian and Braun, who simply wrote: "Proud of you."

Liam Payne, who rose to fame in the British boy band One Direction, seemed particularly moved by Bieber's forthrightness, and disappointed that many headlines focused on the singer's admitted drug use. "I think what you did yesterday was incredibly brave and you deserve a little more respect," Payne tweeted, using Bieber's handle.