Life for Katie Thurston was pretty rosy as she entered her 33rd year."No fancy photoshoot, no posing with dessert, just simply me at 33 today :)," the former Bachelorettewrote on Instagram Jan. 3, 2024. "Happy and healthy."She was doing what she loved—including stand-up comedy—and finding love, with her meeting and getting engaged to comedian Jeff Arcuri in the past year.They began planning their future together. But less than six weeks after Katie celebrated her 34th birthday, her world turned upside down when she was diagnosed with stage 3 breast cancer.It was "the worst feeling I’ve ever felt," she recalled on the March 19 episode of Good Morning America. "You’re just devastated. You’re so devastated. It’s so shocking. As a 34-year-old woman, you're not prepared."Katie first grew concerned when she discovered a lump in her breast last summer. Initially, she thought it might be related to her period, soreness from working out, or from a benign cyst in her breast she had removed when she was 20. But when the lump didn’t go away months later, the reality star decided to get it checked out.