The diagnosis: Stage IV cancer of an unknown origin. Doctors gave her six months to live without chemotherapy, five years if the treatment is successful.
"I was doing the math in my head about how old they would be when I was supposed to die and I just -- it broke my heart," said Cox, who has a 6-year-old daughter and a 6-month-old son.
But rather than sit by and count down the days, the young mother told ABC affiliate WCIV in Charleston she's going to hold on as long as she can. And she's determined to make it a long time.
"I'm going to grow old with my husband and I'm going to watch my babies have babies," Cox said. "My world revolves around them. And that's all I want is to just be here for them."
The young mother is turning that heartbreaking diagnosis into something that's inspiring thousands of others, sharing about her journey on her blog, which she titled "This Little Light of Mine."
There she writes about everything from her reaction to her diagnosis to the way cancer has changed her outlook on life for the better.
"I am thankful for the changes I have made in myself since I found out about that ugly cancer," she wrote in one post. "I am happy. I am in love with life."
Cox wrote that she has a new appreciation for her family and cherishes every moment with them, arranging to make special memories like a photo shoot in the park.
She also writes about her conviction that she will conquer cancer, a conviction that she credits to her faith.
"Why am I so sure I'm going to beat this? Aside from having total faith in God and in prayer, I am sure because I have to be," she wrote.
Though it was started only a week ago, her blog has reached thousands, ABC News reports. Cox wrote that she hopes that her journey inspires other people, with and without cancer, to cherish every moment.
"I want them to hug their children a little tighter," she wrote. "I want them to believe in miracles, because I will get my miracle."
Read more on Cox's blog.