Billie Lourd is opening up about losing her mother Carrie Fisher.

The "Star Wars" icon died five years ago on Dec. 27, 2016, at age 60 after suffering a heart attack. One day later, Fisher’s mother (Lourd’s grandmother) Debbie Reynolds died at age 84.

The actress took to Instagram on Sunday and shared a heartfelt throwback snap of herself as a child next to her smiling mother and a koala.

"People always ask me what stage of grief I'm in," the 29-year-old captioned the post. "And my answer is never simple. I'm in a different stage of grief in each moment of every day."

BILLIE LOURD TALKS 'BRUTAL' LOSS OF CARRIE FISHER, DEBBIE REYNOLDS: 'IT'S REALLY HARD FOR ME'

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Billie Lourd lost her mother Carrie Fisher five years ago.  (Photo by Barry King/WireImage)

"My grief is a multi course meal with many complicated ingredients," she shared. "An amuse bouche of bargaining followed by an anger appetizer with a side of depression, acceptance for the entree and of course a little denial for dessert."

"And that’s how grief should be - all things all at once - actually there is no ‘should’ in grief - grief just is whatever it is for you and that is how it ‘should be,’" Lourd continued. "Ps for anyone wondering why I’m posting this on the 26th it’s the 27th here down unda (aka Tomorrowland) so what better thing to post for my Momby’s Australian death anniversary (4 words I never thought I’d be putting next to each other?!?) than this picture of her and I with a koala!?"

"Sending my love to anyone out there who needs it," the star concluded her post. "I miss you Momby."

The official Instagram account for Fisher’s beloved pooch Gary Fisher also honored her.

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(L-R) Actress Carrie Fisher, honoree Debbie Reynolds and Billie Lourd pose in the press room at the 21st Annual Screen Actors Guild Awards at The Shrine Auditorium on January 25, 2015, in Los Angeles, California.   (Steve Granitz/WireImage)

"It’s been 5 years and not a day goes by without me thinking of you," the caption read. "Gone but never forgotten."

Back in October, Lourd spoke to New Day about the pain she felt in losing both her mother and grandmother.

"It was brutal," she told the podcast. "It was really, really brutal, and I still hesitate and stutter because it’s really hard for me."

Lourd, who is now a mom to 15-month-old son Kingston Fisher with fiancé Austen Rydell, told the outlet that she misses her mom "every day."

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Billie Lourd

 In September, Billie Lourd revealed she welcomed a son with her fiancé Austen Rydell. The baby boy's moniker --  Kingston Fisher Lourd Rydell -- honors Lourd's late mother, Carrie Fisher.  (Jon Kopaloff/Getty Images)

"She was the greatest, funniest person ever," said Lourd. "She was my best f-----g friend ever. There’s no one who will ever be as funny as she is. She was just – she is amazing."