Sex Scandal & Mom's Death: Inside David Letterman's Downward Spiral

David Letterman is spiraling downward in the wake of his mother's death — but it's only his most recent tragedy in a slew of many.

In a new biography on the late-night host, it was revealed that Letterman was forever changed after his 2009 sex scandal.

"I was afraid my family was gone," Letterman said, according to Jason Zinoman, the author of Letterman: The Last Giant of Late Night.

In an interview with People magazine, the 70-year-old confessed that he battled with depression after admitting to multiple affairs with female employees, blindsiding his family and friends.

Now, Letterman has a new slew of heartache, after his mother, Dorothy Mengering, who often appeared on his show, died Tuesday. She was 95 years old.

"The positive response to my appearances on David's show has nothing to do with my amateur abilities as a broadcaster. People enjoy seeing a mother and son together," she wrote in her 1996 cookbook, Home Cookin' with Dave's Mom. "It's that simple."

When news broke of her death, fellow show hosts offered their condolences.