After spending most of her life struggling with obesity and such related problems as sleep irregularity and dangerously high cholesterol, musician Carnie Wilson, 32, has dropped 150 lbs. (from nearly 300) and almost 20 dress sizes from her 5'3" frame since undergoing gastric-bypass surgery in August 1999. Though she has taken some criticism for choosing such a drastic, possibly dangerous method to lose weight -- not to mention having the procedure broadcast live on the Internet -- Wilson tells PEOPLE in its new cover story, "I had no other alternative." And the result? Ten months after the 90-minute operation and already down to 165 lbs., she married her boyfriend of a year, Rob Bonfiglio, guitarist for the band Blush. Purchased after the surgery, her wedding dress still had to be altered twice to fit her shrinking body. "She looked so beautiful," says Bonfiglio, 33, "it was overwhelming." And her favorite new pastime, she confesses to PEOPLE: shopping for clothes.