Michael Strahan’s daughter Isabella Strahan is undergoing treatment after being diagnosed with medulloblastoma, a common malignant tumor that arises in the cerebellum, a part of the brain located at the base of the skull.

The college student and her dad opened up about her health news in a segment that aired on Good Morning America Thursday. She learned about her condition in late October, and underwent emergency surgery at Cedars-Sinai to remove the mass on Oct. 27, a day before her 19th birthday.

“I’m feeling good. Not too bad,” said Isabella, who will start chemotherapy at Duke Children’s Hospital & Health Center in Durham, North Carolina, next month. “That’s my next step. I’m ready for it to start and be one day closer to being over. …. I’m very excited for this whole process to wrap. But you just have to keep living every day, I think, through the whole thing.”

“I literally think that, in a lot of ways, I’m the luckiest man in the world, because I’ve got an amazing daughter,” Michael, 52, said in the interview with his fellow GMA co-anchor Robin Roberts. “I know she’s going through it, but I know that we’re never given more than we can handle and that she is going to crush this.”

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Isabella is one of Strahan’s four kids. The former NFL star has two older children — Tanita, 32, and Michael Jr., 29 — with his first wife Wanda Hutchins, before he welcomed Isabella and her twin sister Sophia with his second wife, Jean Muggli.

In her interview with GMA, Isabella said she first began experiencing symptoms of her brain tumor while beginning her freshman year at the University of Southern California in Los Angeles. “I didn’t notice anything was off ’til probably like Oct. 1,” she said. “That’s when I definitely noticed headaches, nausea, couldn’t walk straight.”

ABC

After Isabella originally shrugged it off as vertigo, her condition took a turn for the worse on Oct. 25, when she woke up in the early hours of the morning “throwing up blood.” Her family encouraged her to seek immediate medical attention.

Explained Michael, “That was when we decided, ‘You need to really go get a thorough checkup.’ And thank goodness for the doctor. I feel like this doctor saved her life because she was thorough enough to say, ‘Let’s do the full checkup.’ “

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After she headed to Cedars-Sinai for a full MRI, doctors discovered Isabella had developed a fast-growing tumor in the back of her brain. It measured 4 centimeters — larger than a golf ball.

Michael was told about the news before Isabella. “It didn’t feel real,” he said. “I don’t really remember much. I just remember trying to figure out how to get to [Los Angeles] ASAP.”

The father of four took off from GMA to be by his daughter’s side, ABC telling PEOPLE at the time he was “dealing with some personal family matters.”

Though medulloblastoma is common, with about 500 children a year diagnosed with it, Michael said it’s “rarely” someone her age. “It’s still scary because it’s still so much to go through,” he confessed. “And the hardest thing to get over is to think that she has to go through this herself.”

Michael Strahan and daughter Isabella.Michael Strahan/Instagram

Following her surgery, Isabella underwent several rounds of radiation treatment, as well as a month of rehabilitation. “I got to ring the bell yesterday,” Isabella told cancer survivor Roberts, 63. “It was great. It was very exciting because it’s been a long 30 sessions, six weeks.”

Her twin sister Sophia was by her side, helping Isabella learn to walk again.

Isabella plans on documenting her journey in a new YouTube series to benefit Duke Children’s Hospital & Health Center.

“It’s been like, two months of keeping it quiet, which is definitely difficult. I don’t wanna hide it anymore ’cause it’s hard to always keep in,” she said on GMA. “I hope to just kind of be a voice, and be [someone] who maybe [those who] are going through chemotherapy or radiation can look at.”

Sophia Strahan, host Michael Strahan, and Isabella Strahan at the 2019 Nickelodeon Kids’ Choice Sports honors.Matt Winkelmeyer/Getty

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She went on to say the experience has given her a new outlook on life.  “Perspective is a big thing,” she said. “I’m grateful. I am grateful just to walk or see friends or do something, ’cause when you can’t do something, it really impacts you.”

And Michael’s also seeing life differently now. “You learn that you’re probably not as strong as you thought you were when you have to really think about the real things, and I realized that I need support from everybody,” he said on GMA. “You think, ‘I’m the athlete, the tough guy, you know, I can come and handle, I’m the father in the family.’ It is not about any of that. It doesn’t matter. And it’s really made me change my perspective on so many things in my life.”