Justin Bieber opened up like never before about his struggles with mental health, past drug use, abusing his relationships, as well as the ups and downs of being a child star.

The "Sorry" singer shared candid details about his troubled past in a lengthy Instagram post on Monday (September 2). In it, he not only shared how fame led him to make "every bad decision you could have thought of," but he also discussed his "heavy" drug abuse and how it affected his romantic relationships.

"I started doing pretty heavy drugs at 19 and abused all of my relationships," Bieber wrote. "I became resentful, disrespectful to women, and angry. I became distant to everyone who loved me, and I was hiding behind, a shell of a person that I had become. I felt like I could never turn it around."

"It's taken me years to bounce back from all these terrible decisions, fix broken relationships, and change relationship habits. Luckily god blessed me with extraordinary people who love me for me," he continued.

The Canadian pop star then revealed his marriage to Hailey Baldwin is what helped him become a better man. "Now I am navigating the best season of my life ‘MARRIAGE'!! Which is [an] amazing crazy new responsibility. You learn patience, trust, commitment, kindness, humility and all of the things it looks like to be a good man," Bieber added.

“All this to say even when the odds are against you keep fighting,” he finished his post.

Read Justin Bieber's full Instagram message, below:

One Direction's Liam Payne later praised Bieber's honest Instagram post, as well as questioned the media's decision to focus on his drug use confession instead of his mental health struggles.

"So this is the one thing the worlds media picks up on after all he said," he wrote. "Can anyone else see the problem here?... @justinbieber I think what you did yesterday was incredibly brave and you deserve a little more respect."