DOLLY'S DARKEST DAYS

Retires from tours to stay home with Alzheimer's patient husband Carl Dean

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BELOVED country queen Dolly Parton's stunning announcement that she'll never our again was spurred by a secret heartbreak the 76-year-old Nashville legend is locked in a brutal battle with a killer disease, GLOBE can reveal!

Dolly's struggling to cope with a devastating diagnosis that changed her life - her hubby of 56 years, Carl Dean, 80, is stricken with Alzheimer's and is slowly wasting away, insiders tattle.

Now, she's determined to spend her final days with the man she shunted aside for decades to pursue fame and fortune.

In revealing her decision to end her concert tours, the I Will Always Love You singer was clear it was for personal, not professional reasons.

"I want to stay a little closer to my husband," she explains. "I don't want to be gone for four or five weeks at a time. Something could happen.

"I would not feel right about that, if I were gone and somebody needed me."