A wealthy, 89-year-old artificial sweetener magnate who made Sweet’N Low a household name has committed suicide by jumping from his Park Avenue apartment building, law enforcement sources told The Post. Donald Tober, CEO and co-owner of the New York-based 1,400-employee Sugar Foods, leapt to his death just after 5 a.m. Friday, and was found in the courtyard of the luxury Upper East Side building between 65th and 66th streets, the sources said. He was struggling with Parkinson’s disease, the sources said.