Music super­stars TIM McGRAW and FAITH  HILL are caught up in a $135 million divorce shocker as their 16-year marriage finally hits rock bottom amid furious clashes and suspect­ed infidelities.

Tim feels imprisoned by a de­manding, controlling wife who’s forced him to give the boot to his longtime buddies and even put his beloved 750-acre Nashville-area ranch up for sale.

Meanwhile, Faith is outraged by the “Southern Girl” singer’s reputation for a roving eye and es­pecially fears his tight friendship with seductive young country star rival Taylor Swift – who’s half her age.

The couple’s life has turned into a battlefield, and now Tim is threatening to walk for good, say sources!

An exclusive ENQUIRER in­vestigation has uncovered the sensational details of the conflict that’s left the superstar couple’s marriage and their $135 million empire hanging by a thread.

“I’m treated like a dog!” a fed up Tim recently raged about Faith, according to an insider.

And a close source revealed: “He feels he needs to stand up for himself and get his manhood back. He feels like Faith has a leash around his neck – and he wants out of her prison!”

At the root of the conflict is mutual mistrust – both suspect each other of infidelity.

“For years, Tim has been at the receiving end of cheating rumors, but the truth is that Faith’s flirty nature toward other men – includ­ing some of Tim’s closest friends – has caused a big part of the prob­lems in their marriage,” confided an inside source.

A few years back, Faith, 45, was on tour with 46-year-old Tim and became very friendly with another country singer.

“Tim caught the singer mas­saging Faith’s feet,” revealed the source.

“He hauled off and punched him and then started lashing out at both of them!

“The only thing that stopped the men from beating each other senseless was that Faith got be­tween them, but it didn’t end there.

“Tim was so angry he contin­ued to pick fights with Faith, and she kicked him off his own tour bus and made him ride with his former band.”

Around the same time, Faith, who was pursuing a movie career, caught the eye of Kevin Costner – which nearly sent Tim through the roof, insiders say.

“Kevin and Faith really hit it off and began discussing working together on film proj­ects,” said the source. “It was all completely innocent, but drove Tim nuts.

“Tim barred Costner films from his tour buses – and even banned the mention of his name.”

But Tim’s trust issues are only part of the problem – Faith also goes on jealous tears.

“Taylor Swift is Faith’s biggest worry,” the close source told The ENQUIRER.

In a recent interview, Tim com­plimented Taylor saying she is both young and beautiful.

 “Tim keeps telling Faith there’s nothing to it, but Faith doesn’t believe him.

“Taylor is just 23 and gorgeous, and Faith sees her as the biggest threat to her marriage.”

A bunch of unsavory stories about Tim’s wandering eye have gotten back to Faith over the years, and that’s been putting increasing strain on the mar­riage.

One time Tim and some pals went on a Mon­tana outdoor adventure.

“While on that camping trip, Tim met a girl,” said the source. “The relationship never evolved into anything more than a friendship but, once again, when Faith found out he was spending time with this girl, she went ballistic.”

Tim has insisted time and time again that there have been no other women in his life, but their marriage remains plagued by jealousy, which is not surpris­ing since they were both engaged to other people when they met.

Faith has added to the problems by insisting that Tim dump his hard-drinking, hard-partying buddies, including Kenny Chesney, who once ended up in a Buffalo, N.Y., jail after the two were involved in a brawling escapade.

Now Tim misses his bar-hop­ping buddies more than ever, say sources, and Faith continues to keep a tight leash on him during his concert tours.

Recently the tension finally came to a head, say sources, when Faith forced him to put their huge Tennessee ranch on the market because she thinks it’s too large for her and their three daughters.

“Tim feels that the ranch is the last thing Faith can take from him,” said an insider.

Despite the turmoil, Tim and Faith remain the King and Queen of Coun­try, selling some 80 million albums and amassing a $135 million fortune, noted the close source, saying: “So far it seems to hold them together.”

But another insider cautions: “Faith thinks she has Tim under her thumb, but she may be in for a big surprise!”