Nick Carter is mourning the loss of his brother, Aaron Carter.

The Backstreet Boys member, 42, posted his heartbreak on social media Sunday, following the news Aaron died Saturday at the age of 34.

Nick posted several throwback photos of the brothers in their youth with a lengthy caption on Instagram.

“My heart has been broken today,” the post began. “Even though my brother and I have had a complicated relationship, my love for him has never ever faded. I have always held onto the hope, that he would somehow, someday want to walk a healthy path and eventually find the help that he so desperately needed.”

The post continued, “Sometimes we want to blame someone or something for a loss. But the truth is that addiction and mental illness is the real villain here. I will miss my brother more than anyone will ever know. I love you Chizz., now you get a chance to finally have some peace you could never find here on earth….God, please take care of my baby brother.”

Aaron and Nick had a tumultuous relationship over the years before the singer’s death.

Back in 2019, Nick announced that he and sister Angel had filed for a restraining order against Aaron, saying in a statement that Aaron allegedly harbored “intentions of killing my wife and unborn child.”

“After careful consideration, my sister Angel and I regret that we were required to seek a restraining order against our brother Aaron today,” Nick wrote at the time. “We were left with no choice, but to take every measure possible to protect ourselves and our family.”

Nick added that he still loved Aaron and hoped he would get “the proper treatment he needs before any harm comes to himself or anyone else.”

Aaron reacted to the restraining order on Twitter that same day, sharing, “So my brother just got a restraining order against me. And I was just served lol.”

“Take care. @NickCarter we’re done for life,” he continued. “I haven’t seen him in four years. And I don’t intend to … I am astounded at the accusations being made against me, and I do not wish harm to anyone, especially my family.”

Nick Carter and Aaron Carter during Howie Dorough's Birthday Party at LAX in Hollywood, California, United States. (Photo by Mark Sullivan/WireImage)
Mark Sullivan/WireImage

Aaron rose to fame in 1997 with his self-titled debut album, followed by Aaron’s Party (Come Get It) (2000), Oh Aaron (2001) and Another Earthquake! (2002).

His early hits included “Aaron’s Party (Come Get It),” “That’s How I Beat Shaq” and his cover of The Strangeloves’ “I Want Candy.” Aaron opened on tour for the Backstreet Boys and Britney Spears before embarking on his first solo tour in 2000.

Aaron appeared alongside Nick and their three siblings Bobbie Jean, Leslie and Angel in their short-lived 2006 E! reality show House of Carters, and he competed on season 9 of Dancing with the Stars in 2009, coming in 5th with partner Karina Smirnoff.

In recent years, Aaron pivoted to rap and released his fifth and final studio album LØVË in 2018, 16 years after his previous album.

The young multi-hyphenate was also an actor, appearing as himself in such shows as Lizzie McGuire and Sabrina the Teenage Witch, as well as roles in 7th Heaven and the movies Fat AlbertPopstar and Supercross.

Additionally, he made his Broadway debut alongside JoJo in Seussical the Musical back in 2001, and he appeared in a 2011 Off-Broadway production of The Fantasticks.

His death came as fans across the internet, and famous faces alike, mourned the loss on social media.

Aaron Carter & Nick Carter during 102.7 KIIS-FM's 2002 Wango Tango at Rose Bowl in Pasadena, California, United States. (Photo by SGranitz/WireImage)

“Fame at a young age is often more a curse than a blessing and surviving it is not easy,” songwriter Dianne Warren shared on Twitter. “RIP Aaron Carter.”

One Tree Hill actor Tyler Hilton wrote that the news was “heartbreaking” after knowing Carter “for years” and taking a liking to him. Hilton and Carter toured together as part of the Pop2K Tour in 2019, and Hilton even played Carter’s hit “I Want Candy” along with him on stage.

“Known him for years and always really liked him, he was warm and really funny,” Hilton shared on Twitter. “Loved putting on a show and he was good at it. I’ll find some pics of us and post more later… damn RIP budddd.”

“Sending love to the family and friends and fans of #AaronCarter. Rest In Peace!” wrote Melissa Joan Hart with a throwback picture of the pair together from their youth.

“Incredibly sad about the passing of Aaron Carter. My thoughts and prayers go out to his friends and family,” tweeted Disney alum Christy Carlson Romano.

On his Instagram Story, Billy Gilman shared a throwback picture, and wrote, in part, “I am gutted by this one. You were truly a musical genius, and I could never just be that.”