Disgraced comedy legend and ultimate TV dad Bill Cosby may not make it to his highly anticipated retrial due to rapidly declining health. Sources tell Breaking Celebrity News that the scandalized ­sitcom star, whose trial for the 2004 sexual ­assault of Andrea Constand ended in a mistrial on June 17, is losing his mind — and facing death!

"Bill is showing signs of dementia," claims a source close to the fallen favorite, whose case ended in a mistrial. "Some of his reasoning skills seem impaired."

Even Cosby's attorney, Brian McMonagle, has been taken aback by his client's health.

"I have been greatly concerned for his health," McMonagle says.

"I have no idea how he managed to sit in a room and endure while strangers were deciding his fate."

If Cosby held on during his two-week trial, he seems to be utterly unraveling in its wake.

"He's been terribly forgetful, and his normal behavior has changed," the source says.

The source also claimed, "He's doing strange things, like cutting a sandwich and eating it with a fork — and it's not because of his vision."

An expert says Cosby's battle with ­dementia most likely won't end well. "Dementia can absolutely lead to death," says health and wellness expert Dr. Gabe Mirkin, who hasn't treated Cosby.

"Dementia is a sign of damage to the brain. When you damage the brain you risk everything else. You can have liver damage, heart damage and damage to every cell in the body."

The expert wonders if Cosby, 80, may be coming apart at the seams due to a secret battle with another disease!

"If he is dealing with dementia and forgetfulness, the odds are he has diabetes," says Dr. Mirkin, pointing out how common the condition is among Americans who store fat in their belly.

"A large ­belly and small buttocks is almost ­always a sign of diabetes. It could be damaging his arteries and increasing his risk of death. His stress level must also be ­extremely high."

The news of his stricken mental state would surely surprise anyone who ­remembers Cosby's air of calm ­competence during his heyday.

From his 1960s role as an undercover intelligence agent on "I Spy" and his never-too-biting comedy routines through his paternal presence on the long-running series that bore his name and his best-selling advice books, ­Cosby exuded common sense and rationality above all.

More shocking under the circumstances is Cosby's current intention to forge ahead with a speaking tour!

"Mr. Cosby wants to get back to work," his spokesman Andrew Wyatt says. "We're planning town halls … to talk to young people."

A source claims the tour would ­extend to other Southern states, ­including Georgia, Mississippi and Florida, ­before swinging north for stops in ­Baltimore and Washington, D.C.