The "Star Wars" legend passed away unexpectedly in December, 2016, just a day before the death of her mum, legendary actress Debbie Reynolds, and the double tragedy left Billie reeling.
However, instead of taking an extended leave of absence from work, Billie agreed to return to the screen in "American Horror Story: Cult", the seventh season of the anthology series, and she's thankful to co-creator Ryan Murphy for offering her an emotional lifeline at the height of her grief.
"When Ryan offered me Cult, it was just a few months after my mum passed, and it honestly helped me process all of my emotions through these characters," the 26 year old tells Entertainment Tonight.
"Being able to cry for (my character) Winter helped me cry for myself," continues Billie. "And it's been really healing and cathartic in an amazing way, and getting to be around all the incredible people on set, they've become like a family to me, and I cannot thank Ryan enough."
She adds, "Honestly, it kind of saved my life."
Billie has remained a part of the cast for the eighth season of the show, titled "Apocalypse", and she is determined to stay on for as long as possible.
"I love doing this show," she says. "It is so much fun and so challenging and has taught me so much. I would do as many seasons as they would offer me. I mean, obviously I would like to do, like, a sweet romantic comedy on the side too, but, like, this is my jam. I love this show so much. And I would do anything Ryan asked me to do. I trust him with all of my heart."
Prior to joining the cast of "American Horror Story", Billie had worked with Ryan on another TV hit, "Scream Queens", which ended its two season run in 2016.