She's doing an Oscar-worthy job of covering up and channeling all of her energy into her career, but word is that Miley Cyrus is super torn up over ex-fiance Liam Hemsworth moving on so quick with actress Eiza Gonzales.

Perhaps that's why Cyrus broke down during her performance of 'Wrecking Ball' at iHeart Radio this weekend?

A source reportedly close to Cyrus said that the singer has moved from the sadness stage and has drifted into the anger and devastation stage.

"Miley is extremely angry," the insider said. Yeah, well, duh. Her ex-fiance was seen making out with another woman like a DAY after their split was announced to the media.

Her tough, tongue-and-twerk façade is just that – a cover-up. "She’s saying she doesn’t care about Liam, that she’s better off without him, all that kind of stuff. But the truth is she’s pretty devastated," the source said.

Again, we get that. We'd expect her to be pretty torn up. But in public, she is keeping up appearances and acting turnt up. At least she has 'Bangerz' on which to focus.

The source further shared, "She totally believed that no matter what happened, she and Liam would work it all out. She thought he was her soulmate. Him just walking away like this and not fighting for her, is heartbreaking. It’s a sad situation, but everyone in her life feels like it’s for the best."

Apparently, Hemsworth was anything but faithful. The insider said, "He’s been making her life hard for a long time. She’s starting to wake up to the fact that Liam was cheating on her all along, so of course she feels betrayed and angry."

He came in like a wrecking ball.

Hopefully, Hemsworth can see a photo like this and eat his heart out. Miley's got that down south rump!