TV legend MARY TYLER MOORE has uttered the heartbreaking words that her fans never wanted to hear: “I’m ready … just let me die!”

Sources shared the actress’ devastating secret with The National ENQUIRER as her family seemed to be preparing for the end after quietly marking Mary’s 78th birthday on Dec. 29.

With Mary helplessly locked in the throes of dementia, loved ones gathered at the Connecticut mansion she shares with her devoted husband, Dr. Robert Levine.

“A birthday cake was brought in, and a few very close friends were on hand to wish Mary well. But she’s faded so badly that she didn’t even know there was a celebration going on,” a source told The ENQUIRER.

“Mary goes in and out of reality. In one of her more lucid moments, she cried out recently, ‘I’m ready … just let me die!’”

Added another insider: “Her family appears to be preparing for the end. There’s nothing more they can do. Mary has refused to go to a hospital or a nursing home. She wants to die at home with dignity.

“It’s heartbreaking. She’s almost completely blind, can barely hear and speaks very little. But she’s ready to meet her maker.”

The once vibrant TV beauty also dreams of seeing her son, Richard Meeker, who died at age 24 in 1980 from a self-inflicted accidental gunshot wound, added the

“Every so often, Mary will say, ‘I’ll be with  Richie soon,’” the source said. “She longs to be reunited with him in death. It’s about the only thing giving her peace.”

Christmas and Mary’s recent birthday were a hard time as her family and home staff realized they likely would be her last, said the insider.

“Calls and well wishes poured in from her longtime Hollywood pals, including Valerie Harper, who played her best friend on ‘The Mary Tyler Moore Show,’ along with former co-stars Georgia Engel, Cloris Leachman and Betty White,” said the source.

“But because of her condition, Mary could barely respond.”

Friends in Mary’s hometown of Greenwich are also devastated over her condition.

Everett Raymond Kinstler, an artist Mary commissioned to paint her portrait in 2008, recently told The ENQUIRER: “Her eyesight was going two years ago when we last heard from her. It’s very sad to think of her this way.”

The last time Mary was seen in public was in April 2013 when she was photographed in a wheelchair at Los Angeles International Airport.

Mary has been losing her agonizing decades-long struggle with numerous health woes, The ENQUIRER has reported.

In addition to her long battle with diabetes, which led to near blindness, she’s suffered kidney and heart disease, as well as Alzheimer’s and dementia-related symptoms. At least nine 911 calls have been made from her home since May 2012.

While some friends have been urging her husband of 31 years to place Mary in a facility, sources said she’s been determined to stay at home “and die in her own bed.”

But indications that Robert has been preparing for the reality that his wife will soon pass has been uncovered in an investigation by The ENQUIRER.

Mary is reportedly worth $100 million, and records show that Robert, Mary’s third husband – who is 18 years her junior – has quietly been managing their assets.

According to property records searched by The ENQUIRER, Dudley LLC, a property management firm registered to her husband, owns her Connecticut estate.

Records also show that Robert, a cardiologist, allowed his professional license to lapse in February 2005.

Robert’s occupation now appears to be managing Dudley LLC and other companies, including SRL Consulting, from the estate.

A Hollywood expert on public records searches, Daniel Portley-Hanks, told The ENQUIRER: “It is not unusual for celebrities to list their properties under company names to protect their privacy.

“But a celebrity who has registered a property to a company would control that company.

“In this case, it looks as if her husband controls everything.”

Added the source: “For decades, money was no object. But now Mary can’t buy what she so desperately needs – a miracle to stay alive.”