Diddy: 'I Can't Even Imagine Life Without' Andre Harrell

Sean “” Combs penned an emotional tribute to , the music executive and Uptown Records founder who died Thursday from heart failure at age 59.

“I honestly still can’t believe it,” Combs wrote on Instagram. “I’ve got to give myself the reality of this in doses. Because I can’t even handle this. I hope to God that you are all blessed to have someone in your life that loves you and believes in you like this man believed in me.… I’m going to miss him so much. I can’t even imagine life without Dre.”

The Bad Boy Records founder also sent condolences to Harrell’s family, including son Gianni and cousin O’Neal McKnight, adding, “LOVE YOU FOREVER DRE!!!!!!!!!!”

Harrell entered the music industry as a member of Eighties hip-hop duo Dr. Jeckyll and Mr. Hyde before becoming an executive. He first worked under Russell Simmons at Def Jam Records before establishing his own label, Uptown, which helped launch the careers of Heavy D and the Boyz, Jodeci and Mary J. Blige, among many others.

Combs worked as an intern at the company before stepping into an A&R role during the Nineties. After being fired from the label in 1993, the rapper/producer went on to found Bad Boy and, two decades later, hired Harrell as vice chairman of his Revolt music network.

In his Instagram post, Combs also linked a video tribute documenting his January speech accepting the Industry Icon Award at the Clive Davis’ pre-Grammy gala. “I want to take the time to thank Andre for being a big brother, for believing in me,” he says in the clip. “Dre, I’m only standing up here because you gave me the chance. You gave me the opportunity … I call you my big brother, but tonight I gotta tell you the truth. I told you my father died when I was two-and-a-half. Andre, you’ve been my father for the last 30 years.”