This Mother’s Day will surely be the hardest for Melissa Rivers without her mother Joan. Rivers writes about the heartbreaking death and humorous life of her mother in her new book, The Book of Joan.

Joan Rivers was the legendary acerbic comedian who poked fun at everyone, including herself.  She died this past summer after a medical procedure at the age of 81.

In her memoir, Melissa Rivers opens up about losing her mother, work partner and best friend. They often worked together on red-carpet awards show specials and reality shows. Rivers admitted in an interview that it was difficult to lose her comedy partner.

“We were Joan and Melissa,” said Rivers. “You knew what you were getting when you heard ‘Joan and Melissa.'”

“I was part of a comedy team, and I’m a straight man,” added Rivers,”It’s going to take me some time to find my voice. I’m still working on that. I think the book is a good step. But it’s hard.”

“I’m lost as a performer right now,” wrote Rivers in the book, “but I will find my own voice. I was taught by the best.”

After Joan’s funeral, Melissa was approached about writing a book about their life together.

“I was walking down the aisle of Temple Emanu-El when a strange woman . . . pressed her card into my hand and made the international sign for ‘Call Me!’ ” said Rivers.

“It was very shortly after her mom’s death, and she was writing this while dealing with her own feelings of grief and loss. It’s very hard to have perspective at that point,” said Suzanne O’Neill, the editor of Rivers’ book.

Rivers balked at first, but soon remembered her mother’s workaholic spirit.

“What would my mother have done?” asked Rivers. “Sell, baby, sell!”

The book has funny anecdotes about her family life and how Joan Rivers was not an ideal housewife.

“Right up until the end of her life my mother believed that, in a pinch, ketchup, Altoids, and Milk Duds were a three-course meal. That doesn’t mean we didn’t sit down to dinner together every night. We did. And my parents would start a meal by thanking God not only for the abundance of food but for the abundance of restaurants offering delivery within thirty minutes,” joked Rivers in the book.

Rivers turned serious when discussing her mother’s death in a Today Show interview. She is suing the doctors that operated on her mother for medical malpractice.

“Yes, it was a tragic accident,” said Rivers. “If something happens, and everyone does everything properly, things happen … You live with it. When it’s error after error, after error, after error, after behaviors that you cannot even begin to get your head around — you get mad.”

In a lighter moment on the Dr. Oz show, Rivers revealed that she was fashion-conscious about her mother’s appearance even when she was at the end of her life. She noted that she had Joan’s makeup done while she was in a coma.

“We brought in everything from our night tables, and then our friend went and we got all of her own bedding and her favorite pretty lounge-y outfit, and I brought in hair and makeup … and they washed her hair and they did her [makeup], and she looked amazing,” said Rivers.

Rivers vowed to move on with her life despite her grief.

“I was raised by survivors,” said Rivers. “People ask, ‘What are you gonna do?’ I’m gonna keep going! What do you think I’m gonna do? What are my choices? Sit in a puddle? Be consumed and lay in a bed? Please! I’d have to put a lightning rod on this house to make sure she wasn’t throwing lightning bolts at me to get out of bed if I let myself wallow.”

“My whole life cannot be about my mother’s legacy,” added Rivers. “I cannot let it consume my entire life.”