We're rooting for you, Brenda Walsh!

Shannen Doherty shared emotional pictures of herself shaving her head amid her breast cancer battle last week, and now the actress is revealing to ET that her disease has spread and requires more treatment.

"I had breast cancer that spread to the lymph nodes, and from one of my surgeries we discovered that some of the cancer cells might have actually gone out of the lymph nodes. So for that reason, we are doing chemo, and then after chemo, I'll do radiation," she explained during a sit-down with the outlet.

The Beverly Hills 90210 star underwent a single mastectomy back in May, but confesses that the uncertainly of living with cancer is way worse than any medical procedure.

"The unknown is always the scariest part. Is the chemo going to work? Is the radiation going to work? You know, am I going to have to go through this again, or am I going to get secondary cancer? Everything else is manageable. Pain is manageable, you know living without a breast is manageable, it's the worry of your future and how your future is going to affect the people that you love," she shared.

Her husband of five years Kurt Iswarienko has been her rock throughout the ordeal, especially when she made the decision to shore off her long brunette locks.

"He was in Mexico working and he was texting nonstop in the middle of his photoshoot like, 'Give me pictures, and are you OK? I wish I could be there.' He was so stricken that he wasn't there with me but I sent him pictures and videos and he was like, 'Oh my God. You're hot with no hair.' So you know, everybody kind of made me feel better about it," she gushed.

The physical ramifications of treatment can't be ignored, though!

"I am in bed and it is a rush to the bathroom. It's, you know, you're throwing up every single second. After my first treatment I lost 10 pounds, instantly. You're throwing up and the last thing you want to do is be in a car. You don't want to be moved, you can't eat. But my husband has to, you know, pick me up. He puts me in the car, he buckles me in, and he drives me to my oncologist and they hook me up to an IV and I get hydrated. ... There's nothing going in my body, it's all going out," she detailed.

She's such a fighter! Go Shannen!