Rob Kardashian Opens About His 'Dark Days,' Says the Moment He Met Blac Chyna, He 'Wanted to Be More Than Frie

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Rob Kardashian is opening up about his relationship with Blac Chyna in his most in-depth interview in years.

The 29-year-old reality star gushes about his pregnant fiancee, and admits he was going through his "darkest times" before finding love again. Rob had sparked concerns among fans prior to his return to the spotlight, when he chose not to appear on Keeping Up With the Kardashians, and skipped out on family events -- like sister Kim Kardashian's May 2014 wedding to Kanye West -- after gaining a noticeable amount of weight. His famous family also openly discussed what they described as his "depression."

"She got me through my darkest times," Rob now tells People about 28-year-old Chyna. "I wasn't happy in my own skin. I missed out on so many things."

WATCH: Blac Chyna Says Her Child With Rob Kardashian Won't Have a 'K' Name, Calls Ex Tyga 'Kinda Cheap'

Although Rob's romance with Chyna came as a shock to fans -- especially given her ties to the Kardashian family, specifically, that she's the mother of Tyga's 3-year-old son King Cairo, and the rapper's now dating Rob's younger sister, Kylie Jenner -- Rob says he's actually had feelings for her for a while now.

"I've been friends with Chyna for a long time," he shares. "From the moment we met, I knew I wanted to be more than friends. She was someone I reached out to for advice. She would cook for me and we'd just talk. She's surrounded me with a lot of positivity."

Most importantly, she also gives him confidence.

"Chyna definitely motivates me," Rob acknowledges. "Being with her got me over the insecurity of being out in public."

"We just want to live our lives the way we want to," he adds. "There were definitely dark days for me, and I'm still not fully happy looking at myself in the mirror. But I'm working towards that. And I'm happy."

As for Chyna, she says she loves Rob just the way he is.

"I saw Rob was willing to better himself," the model, who's been cooking healthy meals for him and motivating him to exercise, tells the mag. "I had never wanted to be tough. I never wanted to change him."

The Kardashian family has definitely given Chyna credit for getting their once reclusive brother out of his shell. In a May episode of KUWTK, Kim praises Chyna for Rob's turnaround.

"She gave him confidence, more power to her," Kim notes. "Even if there's been some drama. If this is what it takes, then I don't care who he's dating. I'm so happy that he's just feeling better about himself."

However, in a new KUWTK clip from this Sunday's episode, Khloe Kardashian -- the sister who's the closest to Rob -- worries that her brother will "go into hiding again" after he and Chyna got into an argument.

"I know when my brother hurts how badly he does hurt," Khloe says. "The more they're fighting and the longer things are bothering him, the more depressed he gets. He'll go into hiding again, go missing. I don't want Rob to live that life anymore."

WATCH: First Look at Rob Kardashian and Blac Chyna's Reality Show -- And Their Big Argument

But earlier this month, a source close to Rob told ET that he was "just going through one of his mood swings, which is common for him," when he deleted all of his Instagram pics with Chyna from his account, but was still committed to filming the couple's new reality show, Rob & Chyna.

"He goes through his dark periods," the source added. "He gets depressed and doesn't want to really do anything, doesn't leave the house. It got better for a bit when he first started dating Chyna, but he's in a rut now. He'll snap out of it."

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