In early 2014, the Heart Wants What It Wants singer, 23, was slated to hit the road in Australia, but two months before she was scheduled to embark on the trek, she unexpectedly cancelled the tour to "spend some time on myself in order to be the best person I can be."

And now, Selena is breaking her silence on the hiatus, confessing to Billboard magazine she was in fact facing complications from the autoimmune disease during the trying time.

"I was diagnosed with lupus, and I've been through chemotherapy," she reveals. "That's what my break was really about. I could've had a stroke. I wanted so badly to say, 'You guys have no idea. I'm in chemotherapy. You're a**holes.' I locked myself away until I was confident and comfortable again."

Now that Selena is feeling much better, she's preparing to release her second studio album, Revival, a record she says was inspired by false rumours of her health and the frustration she had while going through her secret ordeal.

"I'm so f**king nice to everybody, and everyone is so vile to me," she explains. "I've been working since I was 7. I've been a UNICEF ambassador since I was 17. It's so disappointing that I've become a tabloid story. The hate motivated me."

And while her ex-boyfriend Justin Bieber is currently experiencing his own revival in music, Selena insists her former flame holds no bearing with the next chapter in her life.

"No," she insists. "This is my time. I've deserved this. I earned it. This is all me."