Sudden Star — Pamela Sargent

From a Nebula award-winning author, society turns to violence after a  strange celestial body appears in the sky in this dystopian sci-fi thriller.   When what appears to be a star turns its powerful and deadly glare toward earth, the entire planet becomes a living nightmare. Rape, murder and suicide become the norm, and fear grips at the heart of humankind.   One doctor goes against the tide, defying the medical code by providing insulin to a diabetic. But a protocol that was once a routine part of his practice turns Dr. Simon Negron into a criminal. With a young prostitute as his only ally, he goes on the run through a world that grows madder with every waking hour. . . . Published in the UK under the title The White Death.