Trigger Warning: This piece contains mentions of substance use disorders. Matthew Perry is opening up about some of the most difficult moments of his life in his upcoming memoir titled Friends, Lovers, And The Big Terrible Thing.

In it, the 53-year-old actor reveals that while playing Chandler Bing in Friends from 1994 to 2004, his weight fluctuated between 128 and 225 pounds due to alcoholism and addiction.

“You can track the trajectory for my addiction if you gauge my weight from season to season,” Perry writes.

“When I’m carrying weight, it’s alcohol; when I’m skinny, it’s pills. When I have a goatee, it’s lots of pills.”

Perry, who according to The New York Times has been sober for 18 months, estimates he spent around $9 million on getting sober throughout the years. In his memoir, Perry explains that he took 55 painkillers a day and would keep track of the medicine. “When you’re a drug addict, it’s all math. I go to this place, and I need to take three. And then I go to this place, and I’m going to take five because I’m going to be there longer. It’s exhausting but you have to do it or you get very, very sick. I wasn’t doing it to feel high or to feel good. I certainly wasn’t a partier; I just wanted to sit on my couch, take five Vicodin and watch a movie. That was heaven for me. It no longer is.”

Perry recalled one moment throughout Friends’ tenure when viewers likely noticed his fluctuating weight. “Watch the final episode of season six and the first of season seven — the Chandler-Monica proposal episodes,” he writes. “I’m wearing the same clothes in both, since it’s supposed to be the same night, but I must have lost three and a half stone [50 pounds] in the off-season.”

Perry also reveals that he almost died in 2018 at 49 years old. “The doctors told my family that I had a two percent chance to live,” he writes, explaining that his colon burst due to opiate overuse and he went into a coma for two weeks. He then spent an additional five months in the hospital, and underwent 14 operations as a result of his substance use. “That’s a lot of reminders to stay sober,” he says, calling attention to the scars on his stomach. “All I have to do is look down.”

Perry previously told People about his decision to write his memoir, and why the timing was important. “I wanted to share when I was safe from going into the dark side of everything again,” he said. “I had to wait until I was pretty safely sober — and away from the active disease of alcoholism and addiction — to write it all down. And the main thing was, I was pretty certain that it would help people.”

If you or someone you know is seeking help for substance use, call the SAMHSA National Helpline at 1-800-662-HELP (4357).