Stevie Nicks blames the demise of her career in the '90s on a crippling addiction to the tranquilizer Klonopin, and claims if she ever saw the "groupie" doctor who prescribed it to her, she'd "run him down."

The Fleetwood Mac singer recently shared that her addiction to the panic disorder drug was harder to quit then the cocaine habit she had in the '80s.

"They're called tranquilizers for a reason. You stop being so committed," the 66-year-old explained. "This doctor had me on it for eight years. Forty seven days in rehab to get off Klonopin was way more horrific than 30 days to get off coke."

fleetwood mac

Fleetwood Mac members circa 1977 (from left): John McVie, Christine McVie, Stevie Nicks, Mick Fleetwood and Lindsey Buckingham

Her hate for the guy is so strong, in fact, that if she ever saw him, she may not be able to control her rage.

"That doctor is the only person in my life I can honestly say I will never forgive," the musician admitted to Rolling Stone magazine. "All those years I lost — I could have met somebody or had a baby…If I saw him on the street and I was driving…I would just run him down."

In her interview with the mag, Stevie also confessed her shock when her Fleetwood Mac bandmate Christine McVie rejoined the group after walking away in 1998.

Related: Inside the Complicated Romances of Fleetwood Mac

"She sold her house and car and piano and moved back to England, never really to be heard of again," Stevie says of Christine, who blamed frequent panic attacks for her departure. But the now 71-year-old is once again on the road.

"I thought it was gonna be a struggle, to be honest. I was a little anxious," Christine told CBS News. "But actually walking onto the stage…it was much more of a laid-back rehearsal atmosphere."

To read more of Stevie Nicks' interview, head over to Rolling Stone.