New Heartache For Sandra Bullock

She’s one of the world’s most beautiful women – but behind her megawatt smile SANDRA BULLOCK has been bravely hiding the heartbreak over her dying father’s sad final days.

John Wilson Bullock, a former farmer, voice coach and Military Postal Exchange employee, has become a recluse in the huge house he keeps in an upscale suburb of his hometown of Birmingham, Ala., The National ENQUIRER has learned.

“He’s not a well man,” John’s brother Jess Bullock III said in an exclusive interview.

“John has some health issues, but he’s still walking – and was doing great until about three months ago.”

The medical crisis has left 50-year-old Sandra “shattered,” family friends revealed.

John still suffers complications from a near-fatal farm accident when Sandra was a child in Virginia, The ENQUIRER has learned.

He was badly crushed when he fell from a tractor – reportedly breaking his legs, several vertebrae and almost cutting off his left arm.

Doctors initially said he would never walk again and that he may even have to have his legs amputated. But John went through a tough recuperation and got back on his feet.

“That injury has haunted him all these decades, and is still causing him problems,” said an insider.

A neighbor of John confirmed that local residents rarely see Sandra’s father out and about nowadays.

But this past February, the “Gravity” star flew to Birmingham to surprise her dad at his 90th birthday party, with 200 friends and family celebrating at Birmingham nightspot The Club.

“Sandra surprised him by being there,” said family friend Jimmy Koikos. “It was a really nice affair. We’re good buddies. Her dad is the super-sweetest guy I ever saw.”

That could mean John mellowed with age.

When he divorced his first wife, Rita, in 1961 after 17 years of marriage, she claimed in court papers that he “flew into fits of rage. He frequently demanded that I divorce him.

“I was afraid that if I did not accede to these demands that some serious harm might befall me or my children.”

The ENQUIRER exclusively revealed in 2010 that Sandra had since been hiding her father’s “secret family” – including his first wife and two half sisters – away from the public.

After divorcing Rita, John met his second wife, Helga, a German opera singer and voice teacher.

She gave birth to Sandra and younger sister Gesine, but tragically died of cancer at the age of 63 in 2000.

Added an insider: “It was very hard for Sandra when she lost her mom – now she’s really dreading losing her dad!”