'I Love You Guys:' Final Words of Buffalo Bills Player's Fiancée Who Died From Ovarian Cancer Revealed

Brittany Burns was thinking of others until the very end.

Burns, the fiancée of Buffalo Bills linebacker Tony Steward, passed away earlier this month, just two months after being diagnosed with a rare form of ovarian cancer.

She spent her final days with her family in Delaware, reclining on a hospital bed in her family's living room. Her parents, Cathy and Ty, say that even in her final moments, she was thinking of her family and her college sweetheart-turned fiancé.

"I will never forget, she sat up and she hugged Tony really, really tight and she looked at Cathy and said, 'I love you guys,' " her father, Ty, tells PEOPLE of the day the 26-year-old passed away.

Steward revealed her death in a heartfelt Instagram post one day later, and has worked with her family to raise awareness about ovarian cancer through the charity the couple started, " Britt and Tony's Fight Like a Girl Campaign."

Burns' health issues began last October, when she went to a doctor complaining of stomach pains and fatigue. Officials initially thought she suffered from a few ovarian cysts, but during a surgery to remove them, doctors found a tumor.

Both Steward and Burns' parents tell PEOPLE that they were shocked by how quickly the cancer progressed and Steward said the possibility of Burns passing away was the furthest thing from his mind – he even proposed to Burns just days after her diagnosis.

Steward says that the day she died began like "a normal day."

"It was really no different, until later that evening," Steward says. "Later in the evening was when she started breathing a little bit rough and, honestly, it just kind of sounded like it was a little tickle in her throat or something. That's all we thought it was. "

Cathy says one thing was evident in the room that tragic night: love.

"What I remember most about the last several hours is our family was together, Britt was surrounded by family," she said. "There was no doubt, no question that Britt knew how much all of us loved her… as complete as you can be with something as tragic as this.

"We were there for Brittany, we were there for each other, and there was this kind of love in our living room that night."

Burns endured an incredible amount of pain in the months leading up to her death, her parents say.

"It was unbelievable, the pain that she dealt with," Ty says. "The cancer got into her bones, into her liver, but she persevered beyond anything that I could have imagined."

But Cathy says that in the midst of Burns suffering, she focused on comforted her family.

"She was consoling Maia, our younger daughter, because Maia was so upset about what Britt was going through," Cathy says. "And here's Brittany, in incredible pain, trying to pray for the medicines to do their work and fight for her life. And she's being a big sister."

Now, Burns family is following her lead. Steward, Burns parents and her younger sisters are doing all they can to contribute to ovarian research and help other women suffering from the disease.

As of Friday, the campaign has raised nearly $50,000.

"Cancer won the battle, we're going to win the war," Cathy tells PEOPLE. "We have the platform and the commitment to do that."