The 'Dreams' singer was prescribed Klonopin - which is usually used for seizures and panic disorders - in 1986 after she overcame cocaine addiction and she insists the substance "ruined" her life for eight years.
Stevie, who started taking Klonopin when she was aged 38, said: "The only thing I would change about my life is walking into that psychiatrist's office who prescribed me Klonopin. That ruined my life for eight years.
"God knows, maybe I would have met someone, maybe I would have had a baby.
"That was my prime eight years. That was a big mistake. Everything else was exactly how it should have been."
The 'Dreams' singer blames the Doctor Who prescribed her the drug for the toll it took on her health.
She added to Foxnews.com: "That was just a stupid doctor making a groupie mistake and just wanting me to come in there, tell him about all my music friends and young Hollywood, and that nearly ruined my life and nearly killed me."
Since she made her 2001 solo LP 'Trouble in Shangri-La', Stevie - who has sold over 140 million albums with Fleetwood Mac and as a solo artist - acknowledges the music business has changed, but felt she "needed to" make her new record 'In Your Dreams'.
She added: "It is huge pressure, but I needed to make a record, I needed to write songs and be the artist that I have always told everybody I am.
"I'm sorry that the music business is a mess and I'm sorry that internet piracy has taken over, but this is not going to stop me from being an artist. But I don't let myself get excited about anything until I know it is doing well. I don't want my feelings hurt."