Riley Keough Shares Touching Tribute to Late Brother Benjamin: 'This Is True Heartbreak'

Riley Keough has penned a heartbreaking tribute to her late brother Benjamin, who died by suicide on July 12 at the age of 27.

Benjamin Keough was the son of Lisa Marie Presley and grandson of Elvis Presley. Lisa Marie’s rep, Roger Widynowski, previously told PEOPLE that the star is "beyond devastated" over the death of her son, whom she shared with ex-husband Danny Keough.

Older sister Riley, 31, spoke out about her brother’s death for the first time on Saturday, sharing a collection of photos on Instagram, featuring Benjamin alongside a message for him, calling him her “twin soul” and “best friend.”

“Mornings are the hardest,” the actress began. “I forget you’re gone. I can’t cry because of the fear that I will never stop. A pain that’s new to me.”

RELATED: Benjamin Keough's Friend Says He Struggled with 'Pressure' of Presley Family Name Prior to Death

RELATED: Lisa Marie Presley 'Inconsolable and Beyond Devastated' Following Son Benjamin's Apparent Suicide

Riley’s caption continued, “You. There are no words for you. Angel is the closest I could think of. Pure light. Baby brother. Best friend. Wild man. Intellectual. Witness to my life. Twin soul. Protector. Too sensitive for this harsh world. I hope you give me strength to endure the giant hole you’ve left in my heart. I hope you give me the strength to eat. I hope you’re cradled in love. I hope you feel my love. I hope you feel god. You are god. I can’t believe you’ve left me.”

“Not you sweet Ben Ben,” she concluded. “Anyone but you. I guess this is true heartbreak. I hope we meet again.”

In addition to Benjamin, Riley has 11-year-old twin sisters, Harper and Finley, whom Lisa Marie shares with ex-husband Michael Lockwood.

Riley Keough/Instagram

The mother of four is “trying to stay strong” for her daughters, according to rep Widynowski.

"She is completely heartbroken, inconsolable and beyond devastated but trying to stay strong for her 11-year-old twins and her oldest daughter Riley," he said. "She adored that boy. He was the love of her life."

Benjamin’s friend, musician Brandon Howard, recently told PEOPLE that the pressure to live up to the Presley family name "absolutely" contributed to Benjamin's struggles.

"That kind of pressure is definitely a part of what happened," he said. "It's a tough thing when you have a lot of pressure with your family and living up to a name and an image. It's a lot of pressure. It's almost like you're pressured into having to be a musician, having to be an actor. It was good for him to go around the world and discover himself and have his own friends. You never know what triggers it. You never know ... It's so random."

If you or someone you know is considering suicide, please contact the National Suicide Prevention Lifeline at 1-800-273-TALK (8255), text "STRENGTH" to the Crisis Text Line at 741-741 or go to suicidepreventionlifeline.org.