The actress confirmed she was fighting breast cancer a year ago (Aug15) and last week (ends22Jul16) she posted images of herself shaving off her hair as she undergoes treatment to tackle the disease.

Now, in an emotional and candid interview with news show Entertainment Tonight, which will air next week (beg01Aug16), she talks about the toll her health crisis is taking on her body.

In a preview of Monday's episode of ET, Shannen breaks down in tears as she discusses her new bald look.

"It's hard," she says. "I started thinking that I wasn't going to live... I don't look past today."

The 45-year-old, who was first diagnosed with the disease in February, 2015, adds, "I don't know if I'll ever look like me again."

In the three-part interview, the actress admits shaving off her brunette locks was a huge deal - and one she could not do alone - but thanks to family and friends, she's determined to battle cancer - and win.

"I want to believe that if I fight," she says. "I'm gonna be OK."

The actress documented her hair makeover on Instagram on 19 July (16) by revealing her long locks had been exchanged for a close cropped look. In the caption, she wrote "Step 6" and proceeded to share pictures counting down to step one, where she is being comforted by her mum Rosa ahead of the radical change.

In the series of photos, Shannen can be seen taking a pair of scissors to her own hair to cut it down to a short style with the assistance of her model friend Anne Kortright-Shilstat.

Anne shared a selfie with Shannen, sporting her new crop, on Instagram and wrote, "@theshando I couldn't be prouder of you today. Your strength and courage is so inspiring and I am so very lucky to have you in my life. Thank you for blindly trusting me today to help you with such a big step. I will forever be there for you no matter what. #f**kcancer."

Shannen appeared on U.S. TV programme The Dr. Oz Show to discuss her cancer diagnosis in February (16), and revealed she was taking medication to shrink the tumour but she may still require a mastectomy.

Shannen, who married film producer Kurt Iswarienko in 2011, blames her former business managers for preventing her from catching the disease earlier on because they failed to pay her health insurance, and the cancer has since spread to her lymph nodes. She took legal action against them last year (15), which is how her cancer battle was revealed.