Okay. I'm lost.

It's neither, this film is the visual equivalent of a puddle of mud, they didn't know the story they wanted to tell hence everything is up for interpretation, which is never good.

Essentially, the movie is about a ballerina who is pushing herself so hard, she becomes consumed by the role she has taken.

It's easier to understand if you just keep in mind that she's pretty much suffering a nervous breakdown.

Can't stop the signal.

I agree with your interpretation.

She's also suffering a mental illness.

She's mentally sick cuz Anakin strangled her soooo hard causing asphyxia. Affected brain

Born2Burn

She definitely has mental problems, as evidenced by her self-harming, an OCD problem that seems to have been going on for some time. She's obsessed with Beth (witness her compulsive kleptomania when it comes to Beth's things.) She has bulimia, and she's been infantalized by her mother. She's at the right age for schizophrenia to manifest.

I like how you combine Nina and Lily into a single Lena, which seems pretty appropriate to the way we would like to think of Nina's "white" side and "dark" side ultimately blending and combining, creating a whole, unified personality.

The film is an excellent example of what is called the "unreliable narrator." In most stories, the narrator sees all, knows all, and tells only the truth. In the case of the unreliable narrator, we see things from a narrow, flawed perspective, and thus prevented from seeing actual reality, only that character's perception of it. In this case, we see everything from Nina's point of view, and that colors everything that transpires on screen. She is clearly hallucinating at points, manifestations of her desires, fears and insecurities. This also makes it hard to tell who characters really are - is Thomas a sexual predator, or an enthusiastic director pushing his star? Is the mother controlling and smothering, or is she trying to protect a daughter who has serious mental issues? Is Lily a supportive friend, or back stabbing rival?

Consider also the story of Swan Lake - the Black Swan seduces and steals the prince from the White Swan. Nina represents both Swans. She is the Black Swan stalking Beth, stealing her things in order to emulate and eventually become her. Like the White Swan, Beth ends up killing herself (or trying to by stepping into traffic) once Nina has succeeded in supplanting her. Once she wins the lead, her own insecurities and neuroses, create a jealousy of the Lily, nominally the Black Swan she fears is going to replace her (though the name Lily might imply something different).