Flavor Flav spent up to $2,600 a day on drugs for six years.
The Public Enemy founding member, 63, celebrated two years of sobriety in October, but has now told how he splashed out more than $5.6 million over a six-year period during the height of his addiction.
He said: "There was a time that I was spending $2,400 to $2,600 a day... for six years straight, you do the math. That's how much I spent on drugs."
Flav was also selling drugs, but admitted he was his "best customer".
He explained: "I ain't gonna lie, I sold a lot. But I was my best customer ... I had a lot of money at the time too, I was just doing the wrong things with my money."
The 'Harder Than You Think' hitmaker admitted it was "hard as hell" to ditch drugs, but he did so in 2020 and remains sober.
He told the 'Off the Record with DJ Akademiks' podcast: "I guess God wanted me to live. And he knows that I'm a mouthpiece to the world.
"So, I feel that God let me live through that, so that way, I could teach people about the mistakes that I made. And hopefully, they won't make them later on in life.
"Drugs are easy to get on, and they're hard as hell to get off of.
"Back in the days, when we used to make drug records, we used to talk about selling drugs.
"Talking about who can make the most money off drugs, who's balling off selling drugs. It was a competition thing to all of the hustlers.
"Now today's music, we're talking about doing drugs. So, there's a big change within the music ... It's giving younger kids the wrong idea."
Flav also had someone looking down on him in December 2021, when he escaped death after a giant boulder struck his car.
The rapper was returning to Los Angeles from Las Vegas when the heavy rain caused a boulder to fall down a cliff-side and then smash into the right side of the vehicle.
While he briefly lost control, he was able to get to the side of the road.
He later said "God is good" and added that he "came very close to death but is super grateful to be alive".