Shannen Doherty is providing insight into her health journey. 

The Oliver James MontgomeryBeverly Hills, 90210 alum—who was diagnosed with stage 4 breast cancer in 2020—shared that she's been feeling "exhausted" ahead of beginning a new round of chemotherapy treatment.

"It becomes very real in an incredibly different way," Shannen said during the June 24 episode of her Let's Be Clear podcast, "because I have no idea how long I'm gonna be on the chemo for."  

Noting that she's uncertain whether the treatment will go on for several months or "if after three months, it's not working, if we're gonna change again," the Charmed actress added, "That's not something that I can predict. It's not something my doctors can predict. And it's scary." 

And Shannen's new treatment for cancer—which has spread to her brain and bones—isn't the only life change that has caused her anxiety as of late. The 53-year-old shared that her ongoing divorce battle with ex Kurt Iswarienko—who she split from in April 2023 after 11 years of marriage—has also made her feel as though she's "walking into the unknown."

"I just feel like my life has been unknown for over a year now," Shannen explained, "between divorce and cancer."

But while the past few years have certainly been difficult, she noted that those challenges have allowed her to shift her attention to what really matters. 

"I feel like a lot of clutter is out of my life now and things are much more clear and focused," Shannen reflected during a March 11 episode of Let's Be Clear. "I know what I want for myself, and I know how I want to wake up every morning. I just see things in a different light because of the year and a half that was hell."

She added, "I can say that I've had a really blessed life and that I'm an incredibly lucky human being."

Keep reading to look back on Shannen's evolution through the years. 

For the latest breaking news updates, click here to download the E! News App