The ‘Beverly Hills, 90210’ star opens up in PEOPLE’s latest cover story about her Stage 4 cancer diagnosis and how she hopes to inspire others by focusing on her future

“I don’t want to die,” she asserts as a sliver of Los Angeles sunshine falls across her face on the set of her PEOPLE cover shoot four days before Thanksgiving.

The actress — who is best known for her roles on the hit ’90s TV show Beverly Hills, 90210 and later, Charmed — is characteristically candid, upbeat and dry-witted as she opens up about her Stage 4 breast cancer that has spread to her bones.

As she continues to receive treatment, the 52-year-old is more determined than ever to keep moving forward. “I’m not done with living. I’m not done with loving. I’m not done with creating. I’m not done with hopefully changing things for the better,” she says, cracking a smile. “I’m just not — I’m not done.”

Doherty’s eight-year journey with cancer has led her to reflect on the big picture of her life, a theme she will explore on her memoir-style podcast, Let’s Be Clear with Shannen Doherty, premiering Dec. 6 on iHeartRadio, where she plans to discuss everything from career highlights and past relationships to the numerous stages of her illness and health regimens.

After her initial breast cancer diagnosis in 2015 that she first shared with PEOPLE,Doherty had a mastectomy and underwent chemotherapy and radiation.

In April 2017, she revealed on Instagram she went into remission. But by 2019, the cancer returned — and she announced her diagnosis of metastatic stage 4 cancer the following year.

“When you ask yourself, ‘Why me? Why did I get cancer?’ and then ‘Why did my cancer come back? Why am I stage 4?,’ that leads you to look for the bigger purpose in life,” she explains.

She hopes to raise awareness and funds for cancer research — while showing that people with terminal cancer still have plenty to contribute to the world. “It’s insane to me [that] we still don’t have a cure,” she says.

In June, Doherty shared on Instagram that the cancer had spread to her brain and that she had undergone surgery five months earlier to remove a brain tumor. With dark humor, she named it Bob.

“He had to get removed and dissected to see his pathology,” she explains. “It was definitely one of the scariest things I’ve ever been through in my entire life.”