The star has won critical acclaim for her portrayal of the tragic jazz icon in Lee Daniels' "The United States vs. Billie Holiday", but Andra lacked confidence in her own performance, even though her fellow cast and crew members were telling her otherwise.
"I truly was definitely out of my depth the entire time," she told People.com. "I had to just trust what my cast was saying or what Lee was saying."
"I would have the thought, in my mind, that maybe they're just settling because they realized they can't get any better from me. Or that's the best they're going to get, and I'm already here. So there was always that underlying thought that they're just accommodating me right now."
Even after filming wrapped, Andra, who really threw herself into the role by picking up a smoking and drinking habit, was so sure she had messed up the big gig, she quietly decided she "was retired" from acting.
She has since had second thoughts about quitting the big screen, although she insists any new acting role will have to really jump out at her.
"The reality is, if I'm agreeing to do roles, it has to grab me, the way Billie grabbed me," she shared. "And I don't mean like being intrigued, meaning my spirit has to be sort of be called out to it. Because that's really what Billie was."
Andra will be competing for the Best Actress honor at Sunday, April 25's Oscars, where she will face competition from Viola Davis ("Ma Rainey's Black Bottom"), Vanessa Kirby ("Pieces of a Woman"), Frances McDormand ("Nomadland"), and Carey Mulligan ("Promising Young Woman").