"The more time went by, the more something just happened, and 'Oh my god – I want to love someone freely and walk down the street and hold my girlfriend's hand,' " she tells Flare magazine in its June issue.
The 27-year-old actress admits that she was "very nervous" and "deeply emotional" when she made the announcement at the Human Rights Campaign Foundation's first Time to THRIVE conference, where she said she was "tired of lying by omission."
Celebrities applauded Page's decision to speak out, and Jane Lynch told PEOPLE the actress should be easier on herself. "She should give herself a break and not call it 'lying,' " the Glee star said. "But I know what it is to feel like you can't be open and honest about your orientation."
Page says that self-acceptance has been one of her most difficult hurdles, and yet not being openly gay made her feel in the wrong.
"You think you're in a place where you're all, 'I'm thrilled to be gay, I have no issues about being gay anymore, I don't feel shame about being gay,' but you actually do," she says. "You're just not fully aware of it. I think I still felt scared about people knowing. I felt awkward around gay people; I felt guilty for not being myself."
"You hear things like, 'People shouldn't know about your life because you're creating an illusion on-screen.' But I don't see other actresses going to great lengths to hide their heterosexuality. That's an unfair double standard."
In fact, Page says she feels "more creatively inspired than I have in years, and I'm sure it has to do with a lot of bricks being taken out of the backpack." And the actress will star in one of film's largest franchises, X-Men: Days of Future Past, playing Kitty Pryde.
The June issue of Flare is available on newsstands May 12.