The interview in the pages of Vogue is also the first the 24-year-old singer has done in years.
"I got really depressed on tour. I haven’t talked about this, and I’m still processing so much stuff that I haven’t talked about. I was lonely," he told the magazine.
Fast forward two years and the Biebers are completely candid in the magazine, saying things aren't all rainbows and sunshine.
"It’s been so hard for me to trust people. I’ve struggled with the feeling that people are using me or aren’t really there for me ... I’ve made some bad decisions personally and in relationships," Justin admitted. "Those mistakes have affected my confidence in my judgment. It’s been difficult for me even to trust Hailey. We’ve been working through stuff."
Hailey, 22, added, "The thing is, marriage is very hard."
The model and TV host also dropped a bombshell about their on-and-off romance over the past few years.
"Negative things happened that we still need to talk about and work through. Fizzled would not be the right word—it was more like a very dramatic excommunication. There was a period where if I walked into a room, he would walk out," she said.
But by June of last year, they reconnected and were married in September.
Bieber said Hailey is what he's always been missing.
"I’m the emotionally unstable one ... I just feel like I care so much and I want things to be so good and I want people to like me. Hailey’s very logical and structured, which I need," he explained.
Bieber also opened up about his past, his famous DUI a few years back, his public antics, relationships with women and more.
"I found myself doing things that I was so ashamed of, being super-promiscuous and stuff, and I think I used Xanax because I was so ashamed ... Drugs put a screen between me and what I was doing. It got pretty dark. I think there were times when my security was coming in late at night to check my pulse and see if I was still breathing," he said.
But Hailey is his rock and he's in a better place now, he said.
"I love him very much. I have loved him for a long time," she added.