Tim McGraw has no problem admitting he hasn't always walked the straight and narrow. The singer was once a heavy partier -- and drinker -- but shares that when he realized he could lose the most important things in his life, he made a conscious decision to stop.

So, what was it that made him stop partying? His beautiful family, of course. McGraw says it was an easy decision after "realizing you're gonna lose everything you have." The 2015 Taste of Country Festival headliner did it all to save his relationship with wife Faith Hill and three daughters Gracie, 17, Maggie, 15, and Audrey, 12. Ultimately, it was Hill that drew the line.

"When your wife tells you it's gone too far, that's a big wake-up call," McGraw tells Men's Health. "That, and realizing you're gonna lose everything you have. Not monetarily, not career-wise, but family-wise."

In the magazine, the 'Lookin' for That Girl' singer divulges it was time to stop when his daughters knew what he was doing. "It got to the point where my kids were getting older, and it was way past the point that they noticed it," he says. "And I noticed that they noticed. That's enough to straighten you out ... I drank too much. I partied too much. And did other things too much. Chemically. No needles or that kind of stuff, but ... use your imagination."

McGraw learned a lot from fellow singer Keith Whitley, whose death in 1989 shook the country music world. "Keith Whitley taught me how demons can overtake you if you let 'em," he explains. "And I was headed down that path. You feel like you're supposed to be 'on' all the time. Then you drink and get onstage, and all of a sudden you feel confident and powerful."

"It becomes a habit," McGraw furthers. "Up until seven years ago, there were not a lot of shows that I didn't have something in my system." The singer is now sober.