He’s performed in giant stadiums in front of thousands, sung duets with superstars like Elton John and wife Faith Hill, and sold out arenas across the country, but country music’s Tim McGraw didn’t begin his career with the confidence he now projects on stage. Dating back to his earlier performances as an emerging artist, McGraw said he relied on a troubling vice to give him the courage to step out in front of an audience.

“I used to have to have a few drinks to get on stage, because I’m sort of an innately shy person,” he told “Oprah’s Master Class” last summer. “To step out on stage and to sing and be in front of people was nerve-wracking for me in a lot of ways. That was the way I got my courage — some liquid courage, with a little Jack Daniels.”

This habit, he added, soon became an addiction and such a crutch that performing seemed impossible without it. “I couldn’t do it without [drinking],” McGraw said.

Despite his reliance on alcohol and his own mother’s concerns about his use of this “liquid courage,” McGraw hadn’t seen the real danger in what he was doing. “I grew up in Louisiana and we used to drink Miller ponies, sitting on a tailgate around a bonfire. I mean, that was part of the culture of growing up for us,” he said.

Looking back on these times with the perspective that comes from sobriety, McGraw said he realized that he spent a lot of time making excuses for his behavior.

“You can come up with a million excuses why you drink too much,” he said. “Lack of confidence, the success that came so quickly, and then some of the things you didn’t realize was trauma, I guess, back when you were 11… I think the older you get, the more you start realizing those things.”

As time went on, McGraw came to the harsh realization for himself.

“It got to the point where I knew that I drank too much,” he said. “I knew that it was affecting my personal relationships, it was affecting my professional relationships, it was affecting my family. It was turning me into a person that I didn’t want to be… I was at a point where I could lose everything that I had in my life, first and foremost, my family. It [was] time to stop. And I stopped.”

In 2008, the night before embarking on another tour, McGraw said he had his last drink. “[I] flew to Florida that morning from being wasted the night before, and started that tour. Haven’t drank since.”

As he said in the 2014 interview, performing completely sober was an entirely new and challenging experience.

“That was the toughest tour that I’ve ever done in my life… to get through that tour not drinking,” McGraw said. “I’d never done it before… I could probably count on one hand the times I’d stepped on stage where I didn’t have alcohol in me, or something. That was the toughest thing about quitting.”

More: McGraw tears up talking about his marriage to Faith Hill

“Oprah’s Master Class” returns for its fifth season on Sunday, Oct. 25, at 8 p.m. ET. Upcoming masters include Ellen DeGeneres, Robert Duvall, Dwayne “the Rock” Johnson, Smokey Robinson, Jeff Bridges, James Taylor and Patti LaBelle.

Also on HuffPost:

– This feed and its contents are the property of The Huffington Post, and use is subject to our terms. It may be used for personal consumption, but may not be distributed on a website.