Black Swan was hard to watch. It is very dark and it is sometimes hard to relate to the characters who seem stereotypical. I suppose one would need to read "Dancing on my grave : an autobiography" by Gelsey Kirkland to judge. It's a "must see" but not an altogether pleasant experience.
See these two excellent reviews. The Movie Slut's is shorter and perhaps more helpful:
Manola Dargis NY Times Review: On Point, On Top, In Pain
Movie Slut Review: Black Swan: Deadly Dancing
13 hours ago