The 48-year-old actress appeared on Tuesday's "Good Morning America," on World Cancer Day, to discuss her diagnosis as a stage four patient.
Doherty's been a staple of American television since the early '90s, starting off as Brenda on "90210" and then landing a lead role on "Charmed." In March 2015, she was diagnosed with breast cancer, but after years of treatment, she entered remission.
When asked why she chose to share the news of her new diagnosis now, the actress explained, "It's going to come out in a matter of days or a week that -- I'm stage four. So my cancer came back," she said through tears, "and that's why I'm here."
Having told only her immediate family and one cast member (Brian Austin Green), Doherty has known about the diagnoses for about a year. Though she was open about her first battle with the disease, she had wanted to keep this one more private.
"I don't think that I've processed it. It's a bitter pill to swallow in a lot of ways," she said, still crying. "There were definitely days where I say, 'Why me?' And then I go, 'Well, why not me? Who else? Who else besides me deserves this?' None of us do. And I would say that my first reaction is always concern about how am I going to tell my mom, my husband."
"You're worried about everyone else around you," noted reporter Amy Robach. "I think so," Doherty replied.
Doherty was battling the disease at the time of Luke Perry's sudden passing. She thought to herself, "Why wasn't it me?"
"It's so weird for me to be diagnosed, and then somebody who is seemingly healthy to go first," she said. "It was really, like, shocking. And the least I could do to honor him was do that show. Like, I still haven't done enough, in my opinion. It's a hard one, 'cause I thought, 'When I finally do come out, I will have worked, and worked 16 hours a day, and it'll be a good [thing].' People can look at that and say, 'Oh my God, yeah, she can work.' And other people with stage four can work, too. Our life doesn't end the minute we get that diagnosis; we still have some living to do."
She credits co-star Brian Austin Green with helping her get through shooting their "Beverly Hills, 90210" reboot, explaining, "I had moments of great anxiety, where I thought, 'I can't really do this.' And Brian was the one person of that group of people that knew that I told pretty quickly and said, 'Here, this is what I'm dealing with.' So prior to shooting, he would always call me and say, 'Listen, whatever happens, I have your back.' And we were able to talk about Luke in a way that was very positive and uplifting and sort of remember a lot of great moments."
To make matters more complicated, Doherty is in the midst of a legal battle with her insurance company, State Farm, after her California home was "severely burned" in the 2018 Woolsey Fire.
"You walked into the house, and it just reeked of smoke," she explained, noting she tried to communicate with the insurance company to no avail. "So I ended up suing State Farm, and the result has been one of the most horrific processes I have ever been through."
Doherty says she's been forced to pay out of pocket for losses she believes should have been covered by her policy, but State Farm told ABC News, "We empathize with Ms. Doherty's health issues and wish her a full recovery. We strongly believe we have upheld our commitment to our customer and have paid what we owe on this claim."
Per court documents obtained by ABC News, State Farm claims it has paid nearly $1.1 million "to clean and repair plaintiff's home and personal properly, and for temporary housing and furniture rental," adding that, "the plaintiff nevertheless alleges she is entitled to additional benefits under her Homeowner's Policy."
Because of this legal battle and the fact that court documents containing details of her health conditions will be made public ahead of the trial, Doherty wanted to own her cancer story.
"I mean, I rather people hear it from me. I don't want it to be twisted. I don't want it to be a court document," she explained. "I want it to be real and authentic, and I want to control the narrative. I want people to know from me."
The actress admitted she has no idea how to manage the fear, telling Robach she's "petrified."
"My mom is a ridiculously strong, courageous human being. So is my husband," said Doherty, stopping to cry, "but I worry about him."
"I think the thing I wanna do the most right now is I wanna make an impact," she added. "And I can make an impact through this lawsuit and by saying, 'Enough is enough with big business and corporations running the little person over. It's not fair, and I'm taking a stand for all of us.' But it's more about how I wanna be remembered for something bigger than just me."