Before she takes center stage to perform a new single at the Sydney Olympics on Friday, Olivia Newton-John spoke to PEOPLE about her battles to survive breast cancer, bankruptcy, divorce and the loss of her father and godchild. "Sometimes," she says in the new cover story, "you need to be confronted with things before you really know your potential." For Newton-John, who will turn 52 on Sept. 26, life since her 1978 movie smash "Grease" has been anything but smooth. Her screen career flopped after a series of duds, though on one of them, "Xanadu," she met dancer Matt Lattanzi, 11 years her junior. They were wed from 1985 to 1996 and had a child, Chloe, now 14. Newton-John won't discuss the reason for the breakup, but today she has a new man in her life: cameraman Patrick McDermott, 44, whom she met four years ago while shooting a commercial. "I hadn't met her before," he tells PEOPLE, "I never had a crush on her or enjoyed her music, and I never even saw 'Grease.' " No matter. "He is her soulmate," says 'Grease' costar Didi Conn. Chimes in Newton-John: "I'm so lucky to be here."