Later this month, Carol Burnett will celebrate turning 90. While her nine decades have been filled with career success, the comedian has also dealt with major loss, including the death of her daughter Carrie Hamilton — one of the three daughters Burnett welcomed with second husband Joe Hamilton — in 2002.

“There’s not a day or almost a moment goes by that she’s not with me,” Burnett tells PEOPLE in this week’s issue. “We worked together, we laughed together, we cried together. She was a force.”

Like her mom, Hamilton worked as an actress. She starred in the Fame TV series as Reggie Higgins, as well as movies Tokyo Pop and Shag. Hamilton also did an episode of Carol & Company with Burnett in 1990, and the two cowrote a play, Hollywood Arms, based on Burnett’s memoir about her childhood.

Hamilton struggled with drug addiction and in 2002 was diagnosed with cancer that started in her lungs and spread to her brain. She died the following January at age 38.

“When she got sick, I remember she was in the hospital and I would go to see her every day,” Burnett recalls. “One day, a nurse at the hospital said, ‘Carrie cheers us up.’ I asked Carrie why she was always cheerful, and her reply was, ‘Everyday I wake up and decide.’ That’s the key word, decide.”

Now, Burnett says, “I say that to myself every morning.”

The six-time Golden Globe winner realizes how fragile life can be.

“It’s taking [it] one day at a time,” Burnett says. “You don’t know. Life can change on a dime. So just be grateful for today what you have.”