Before playing Toby on 'This Is Us' Chris Sullivan once made $150 a week and lived off coupons for free burritos

Today, Chris Sullivan, 38, is a star of NBC's Emmy-winning show "This Is Us," playing Toby, the lovable boyfriend-turned-husband of Kate (Chrissy Metz). The show, which has its season 3 premiere Tuesday, won three Emmys and has been nominated for 18. In February, the episode that aired after the Super Bowl nabbed a record 27 million viewers.

But when Sullivan was 22, life wasn't so glamorous.

"My very first acting job was a production of 'The Fantasticks' at a church in Westwood [New Jersey] for about $150 a week," he tells CNBC Make It.

To make ends meet, he clipped coupons and hunted for deals.

"Frugality was my side hustle. I was really good at it," Sullivan says with a laugh.

"Back then, there was this coupon website that offered all kinds of weird deals at restaurants and things like that. Our friends found this one for Baja Fresh, where if you bought a large drink you got a free burrito. So we printed out about 1,000 and ate burritos for about a year."

It may not have been the easiest career path, but Sullivan says it was his dream. "[Y]our passion will lead you to your purpose," he says. "Obey your purpose above all else."

That's exactly what Sullivan did.

"I decided I was going to be an actor, and [although] I didn't get a job, I saved all of my money and hustled every day, auditioning, trying to get any work I could," he remembers. "Eventually, it slowly built up, a small job to a slightly bigger job to a slightly bigger job to the third season of NBC's 'This is Us.'"

The experience taught Sullivan that the key to success is determination: "Decide what to go be and be it," he says.

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