Dakota Johnson "went into an emotional void" after 'Fifty Shades of Grey'.
The 26-year-old actress - who portrayed Anastasia Steele in the first installment of the raunchy saga - feels like she's been "five different people" since the movie came out earlier this year.
Asked how she decompressed after the film, she said: "I'm trying to think. It came out in February. Where are we now?
"It feels like a lifetime ago. I feel like I've been five different people since then.
"What did I do afterwards? I was working - I kept going. The night I hosted 'Saturday Night Live' was the end of promoting the movie and then... I think I blacked it out. I went into an emotional void."
Though Dakota's mother, Melanie Griffith previously said she didn't want to see 'Fifty Shades', the actress - whose father is actor Don Johnson - hopes she'll see her new movie.
She said: "Sometimes I talk to my parents about work. I keep it separate but I want them to see 'Black Mass'."
Because she is the daughter of two movie stars, Dakota has always enjoyed being on film sets.
She told Total Film magazine: "My childhood I spent outdoors riding horses. It's the most comfortable place for me.
"I grew up travelling. I grew up on sets. I grew up going to new places. And I like it all."