Just a few years ago, Metz was nearing a breaking point resulting from a decade-long spiral of depression and self-doubt, she told PEOPLE in February

Ever since NBC’s smash hit drama This Is Us premiered, breakout star Chrissy Metz has found fame and a calling as a role model for body positivity. And on Sunday night, she is nominated for the Golden Globe for best supporting actress in a television series.

But just a few years ago, Metz was nearing a breaking point resulting from a decade-long spiral of depression and self-doubt, she told PEOPLE in February.

Be sure to check out PEOPLE’s full Golden Globes coverage to get the latest news on Hollywood’s big night.

Credit: Jim Wright

“I’d be getting maybe two auditions a year, and I’d always see the same small group of girls,” said Metz, who was a size 12 when she was first scouted but dropped 50 lbs. at the recommendation of her then-manager before moving to L.A.

With work slow, she took a job as a junior commercial casting agent but said having to backburner her own dreams “was like watching your boyfriend take another woman out every day.”

Depressed and “eating my feelings,” Metz gained more than 100 lbs. before a panic attack on her 30th birthday sent her to the hospital and snapped her back into reality.

She set about overhauling herself physically and emotionally, including following doctor’s orders to lose weight. “I was so gung ho, I lost 100 lbs. in less than five months,” she said. “All I did was eat a 2,000-calorie diet and walk 20 minutes a day.”

As the numbers on the scale fell, Metz regained confidence. Then she landed the recurring part on American Horror Story: Freak Show that would kick-start her career.

Playing a “fat lady” meant stepping into a fat suit. “It was sobering,” she said. “I thought, ‘What if I become that heavy and can’t walk around or get stuck in the doorframe? I was like, ‘I don’t want this for me.’ ”

Credit: Ron Batzdorff/NBC

The role also lead her to This Is Us. Baring her body and stepping on a scale within the first few minutes of the show’s pilot this past September, Metz — through her character Kate — instantly instantly became a fan-favorite.

“You don’t realize that somebody who’s average or even very fit could relate to someone who’s overweight,” she said of the feedback she’s gotten, “but it’s not about our size — it’s how we look at ourselves and how we feel about ourselves.”

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Though there was a bit of blowback to Metz’s prior statements about losing weight in tandem with Kate on the show (Metz now tells PEOPLE her contract with NBC does not mandate a specific workout regimen, any surgery or include an explicit weight-loss target), the actress acknowledged that having her own physical journey tied to Kate’s is a key element of why This Is Us is the role of a lifetime.

“You have to use what you have, and I wouldn’t have this role if I had already lost weight,” she said. “Now it’s about telling a story of a woman struggling with her weight, just as I have and still am.”

As for what’s next, while Metz said she’s taking steps to lose weight, she does make it clear that the stops along her weight loss journey are “not for anybody but myself. … I want to have a fit, healthy body and not have to be put in a box. I don’t want to be limited by anything.”

This Is Us airs Tuesdays (9 p.m. ET) on NBC.

The 75th annual Golden Globes are presented live at the Beverly Hilton in Beverly Hills, California, on Sunday. The show airs at 8 p.m. ET on NBC.