EMOTIONALLY frazzled MARIE OSMOND is hiding a secret heartbreak that has people close to her afraid she’s head­ed for another major meltdown!

The fragile 53-year-old star is still shattered over her late son Michael’s suicide and has been spiraling into the holiday blues while rehearsing for her upcoming “Donny & Marie – Christmas in Los Angeles” show, because it was Michael’s favorite time of year.

“Marie turns into an emotional wreck each time she comes to L.A., but especially near the Christmas holidays because she is so overcome with memories and feelings of guilt over Michael’s death,” said an insider.

Marie’s 18-year-old adopted son plummeted to his death from his 8th floor apartment on Feb. 26, 2010. It happened just a few miles away from where Marie is slated to perform at the Pantages Theater, and sources say it’s proving to be too much for the entertainer to handle.

“Executives on the show have already complained about Marie’s behavior,” said the source. “She’s constantly on edge, barking over triv­ial details and bombarding everyone with a litany of questions about ev­erything from the sound, the lighting and even her dressing room!

“It got so bad that one of Marie’s support people pulled aside a show executive to explain why she’s taken on such a gloomy personality and has become so difficult to work with.

“But Marie’s closest friends have seen this drastic change before, and they’re worried sick she’s heading for another emotional meltdown – or worse!”

Last Christmas, Marie took her entire family to New York to escape from the haunt­ing memories of past holidays spent with Michael. But this year sources say she thought enough time had passed for her to cope with doing the show in L.A.

Sadly, it seems to have been much harder than she ever thought.

In a recent interview with a Brit­ish newspaper, Marie talked about Michael’s death, saying: “It was a terrible time. A lot of people have lost sons and daughters. It’s not a fun club to be part of.

“It never gets better. God gives you little bits of respite, and then suddenly it will hit you, especially around the holidays.”

Marie has a history of breakdowns. She attempted suicide with drugs in 1999 and again in 2006. And, as The ENQUIRER exclusively reported in our Oct. 22 issue, the Las Vegas singing sensation and host of “Ma­rie” – her new Hallmark Channel talk show – once asked loved ones to check her into a mental ward for electric shock therapy to treat her crippling bouts with depression.

Some of Marie’s pals fear her holi­day performances with Donny, 54, will be cut short by her unstable emotional state. But others believe that the trouper in Marie will prevail.

“Chances are theatergoers won’t have a clue how distraught Marie is because she’ll put on such an amaz­ing show. But you can bet she’ll be thinking of Michael the whole time.”