Complex sentence: The Songs and Stories of a Legend was about to open on Broadway, when Parrilli was diagnosed with Sjögren's syndrome and Lyme Disease, which left her unable to sing and ended her singing and performance career.
Split into simpler sentences: The Songs and Stories of a Legend was about to open on Broadway, when Parrilli was diagnosed with Sjögren's syndrome and Lyme Disease. The two conditions left her unable to sing, and abruptly ended her singing and performance career.