Frankie Grande says he owes his sobriety to Mac Miller.
The 35-year-old former Big Brother star shared a photo of the late rapper on Instagram on Wednesday and shared how Miller helped him get off drugs and encouraged him to stay clean. Miller dated Grande's sister, Ariana, for two years before the pair split in May.
Miller was found dead on Sept. 7 after an apparent drug overdose. He was 26 years old.
"I am beyond heartbroken over Malcolm’s death," Grande wrote. "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 of the drugs alcohol and medications I was taking, when I couldn’t imagine living without them. It was the place where I found the community of support that showed me that living life without drugs was a possibility and I would never have discovered that if it weren’t for Malcolm."
Grande recalls Miller being thoughtful on the anniversaries of him getting sober.
"I remember when I would get 30, 60, 90 days clean and Malcolm would be there with a gift and a card and words of encouragement... telling me that he knew how hard getting sober is and how impressed he was that I was succeeding," he wrote. "Addiction is a TERRIBLE disease… many people are suffering from addiction like I am and many many of them are losing. 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," he continued. "This is a difficult road but YOU DO NOT HAVE TO TRUDGE IT ALONE. To anyone who needs help, help is there. You just need to have the courage to ask, which I know can be EXTREMELY difficult... but when you do I GUARANTEE support will be there. Do not be ashamed if you are losing the battle against addiction, shame feeds the disease, humility defeats it. Please ask for help! You are NOT ALONE!"
Grande reveals he has now been sober for more than a year.
"Malcolm my friend, you will be dearly missed," he wrote. "And I know you will be looking down on me from heaven, proud AF for every day I live my life clean and sober... 453 days and counting... Thank you from the bottom of my heart. AA: (212) 870-3400 NA: (818) 773-9999 Suicide Prevention Lifeline: :800-273-9255."
Ariana has yet to speak out on Miller's death, though she did share a sweet photo of him on Instagram. Since his death, she has also disabled comments on her Instagram.
A source previously told ET that Ariana is devastated over Miller's death.
“Although the two ended their relationship, Ariana always shared a deep connection with Mac and wanted nothing but the best for him," the source said. "Ariana is very upset."
On Tuesday, Miller's longtime friend, Shane Powers, praised Ariana for being "unbelievably involved and helpful" with Miller's sobriety journey while the two were in a relationship.
"[Mac and Ariana] were very much in love and I have to say, she was incredible when he was first sobering up," Powers said on the latest episode of his podcast, The Shane Show. "She was a f**king G to him. There could not have been anybody more supportive of him being sober than Ariana. I saw that, I was around it, I took phone calls from her. 'How do I help? What do I do?' This little girl was unbelievably involved and helpful to him being healthy."
"Whether he's an addict or not, the way that Mac partied was not healthy," Powers continued. "[And] there was no one in his life more ready to go to the wall for him when it came to him being sober. [Ariana] was an unbelievably stabilizing force in his life and she was deeply helpful and effective in keeping Mac sober and helping him get sober. She was all about him being healthy. Period."
For more on Miller's death, watch the video below:
Mac Miller Honored by Fans In Hometown Vigil at Pittsburgh's Blue Slide Park
Mac Miller's Friend Says Ariana Grande Was 'Unbelievably Involved' in Late Rapper's Sobriety
Lil Xan Pays Tribute to Mac Miller With New Face Tattoo