“It was like an on-off relationship for four years,” the actress said
Kristen Johnson
Credit: Erik Pendzich/Shutterstock

Kristen Johnston is opening about her past substance abuse and how at one point, it felt like an "abusive" marriage.

The 3rd Rock from the Sun star, 53, got overwhelmed by fame following the success of the sitcom that aired from 1996 to 2001.

"It was like an on-off relationship for four years, and it only became really bad after 3rd Rock," Johnston – who has been sober for 14 years – said on Elizabeth Vargas' Heart of the Matter podcast.

The actress continued, "I was able to keep a lid on it for a couple of years, and then we became married, me and my opiates, a couple of years after 3rd Rock, and it was a very, very abusive relationship."

Credit: James Sorensen/NBC/NBCU Photo Bank

Johnston described handling fame as "absolute panic."

"The work was fun, but everything that came with it was so terrifying to me, and I didn't realize until later that I lived in a state of absolute panic for 10 years," the Austin Powers: The Spy Who Shagged Me actress admitted.

She recalled thinking, "Ugh, I'm going to be found out. I'm being chased by paparazzi. They're going through my garbage. They're going to write crap about it. My mom's going to see."

It wasn't until Johnston starred in a play in London and had to go to the hospital for a ruptured ulcer a day after opening night that she realized she had to end her habit.

Kristen Johnson
Credit: Michael Buckner/Getty

She spent some of her weeks-long hospital stay on New Year's Eve. 

"I saw all these fireworks, and everyone was outside at the Eye, and I could see the London Eye from my hospital bed, and it just occurred to me that there are people standing there watching that outside. They're with their friends and their family, and they are not worried about where their next pills are. I haven't done that for 15 years," Johnston remembered. "That was the first time sanity seeped through."

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Last August, her younger sister Julie Herschede died after she "lost her battle with addiction," the actress said at the time.

"It was just a very painful thing for my family. So, I connect to people who communicate with me, the loved ones of addicts and the addicts, because I've been both," Johnston said.