EXPOSED!  How “The Man in Black” JOHNNY CASH gulped 700 pills a week!  Burned down an entire forest AND was brought back from the dead! PLUS: inside his co-dependent relationship with wife JUNE CARTER CASH!

ON the 10th anniversary of the death of country king Johnny Cash, a bombshell diary is ripping the lid off his shocking secret life revealing the horror of his addictions and the truth about his relationship with his wife June.

The diary is made up of recordings by Cash’s late manager Saul Holiff that span the years from 1960 to 1973. The tapes were discovered by his son Jonathan, who has produced a documentary called “My Father and The Man in Black”.

Jonathan says the diaries drop bombshells about Cash that were glossed over – or ignored – in the hit 2005 biopic Walk the Line, starring Joaquin Phoenix as Cash and Reese Witherspoon as June Carter.

“There’s stuff that’s never been in any book, movie or magazine before,” says Jonathan, who discovered the diary after his dad committed suicide in 2005.

When Saul became Cash’s fulltime manager in 1960, he didn’t realize how addicted the singer was to booze and pills. Cash, who did his best to hide his addictions, was so high while recording a song in 1962, he didn’t notice his hands were bleeding from banging on pipes in time to the music.

A Carnegie Hall concert turned into a “disaster” because pills and booze had ruined his voice. A planned recording of the performance had to be scrapped.

By 1965, the country singer was known as Johnny “No Show” Cash to promoters as Saul found himself canceling performance after performance.

Cash admits on tape to washing down 700 pills with at least 168 bottles of beer every week. “I took all the drugs there are to take, and I drank,” he confessed. “I looked like walking death.”

On June 27, 1965, Cash called Saul and confessed he’d “accidentally” started a fire in California’s Los Padres National Forest destroying 500 acres and killing 49 endangered condors!

The U.S. Forest Service dragged Cash into court to recover the $125,000 cost of putting out the blaze caused by an electrical problem in his truck. When he appeared before the judge, Cash said, “I didn’t do it. My truck did. And it’s dead, so you can’t question it!” But his bizarre statement didn’t get him off the hook. He paid Uncle Sam $82,000, which is about a half-million bucks in today’s dollars!

Then weeks after the fire, Cash was arrested in El Paso, Texas, for trying to smuggle pills into the U.S. from Juarez, Mexico. Authorities found 668 tablets of Dexedrine and 475 tranquilizers on the singer.

Cash later pleaded guilty, was fined $1,000 and received a 30-day suspended sentence.

“It was bad, very bad, misconduct on my part,” he says.

Less than two weeks later, the Man in Black was brought back from the dead in Toronto, Canada, when Saul and band members found him unconscious in the tour bus.

“Johnny Cash was on the floor of the motor home, totally unconscious, no one could pick up any pulse whatsoever,” Saul says on tape. “For all intents and purposes, he was dead.”

But he revived at a hospital, and the next day at a Rochester, N.Y., show, an amazed Saul reports “Johnny…was full of energy…and did two clear-headed, sensational solo shows.”

Still, more pill and booze troubles followed. While onstage at a January 1967 show in Miami, Cash strummed his guitar once, looked at his manager and pleaded, “Saul – help me.”

Saul had pressed Cash to hire on June – and she would save his life. The singer’s divorce from wife Vivian, mom of his four kids, became final on Oct. 21, 1967.

Weeks later, Cash “sequestered” himself to get sober. On Feb. 22, 1968, clean of pills for two months, he proposed to June onstage during a show. She accepted, and they were wed a week later. That year he also made a famous appearance at California’s Folsom State Prison.

“With Carter’s support, Cash kicked his drug habit and became a devout Christian,” a source notes.

“By putting June in the band, Saul saved Johnny’s life. Though he continued to be a wild man for some years after June appeared, she was there for him when he finally decided to get clean – and they became one of America’s most beloved couples.”

And when June died at age 73 on May 15, 2003, Cash, 71, followed her to the grave just four months later.