Fans are still reeling from the news of Mac Miller’s tragic and untimely death on September 7th. In the days since, his fellow musicians and loved ones have spoken out about how the rapper influenced their lives, and now Frankie Grande—Ariana Grande’s half-brother—is doing the same. In a moving Instagram post, Grande opened up about his relationship with the late musician, and how Miller supported him on his own path to sobriety.

“I am beyond heartbroken over Malcolm’s death,” he wrote, using Miller’s given name. “He was a good friend and was wonderful to my sister. He was the reason I went to the rehabilitation center where I was detoxed safely from all the drugs alcohol and medications I was taking, when I couldn’t imagine living without them.”

He went on to detail how supportive Miller was every step of his recovery.

Grande then took a moment to reach out to anyone who might be struggling with addiction. “Addiction is a TERRIBLE disease,” he wrote, “Those of us who are struggling with addiction must stay strong. We must continue to work HARD on ourselves every single day and help each other. Our disease is strong but WE ARE STRONGER and I vow to work every moment of my life to keep myself sober so that i may be there for others. This is a difficult road but YOU DO NOT HAVE TO TRUDGE IT ALONE.”

He concluded by addressing Miller directly:

Frankie’s emotional post comes days after Ariana, who dated the singer for two years, posted a simple black and white photo in his memory.

Rest in peace, Mac. And if you or anyone you know is struggling with addiction, don’t hesitate to reach out to the Addiction and Alcohol Hotline at 844-244-3171.