Article continues below advertisementPrince William opened up about the emotional weight he carries amid his loved ones' medical woes.In a preview of his upcoming appearance on Apple TV+'s The Reluctant Traveler With Eugene Levy, the 43-year-old confessed that King Charles III and Kate Middleton's cancer diagnoses brought him to a dark place.The Prince of Wales wanted to remain positive but found it difficult to maintain hope.Article continues below advertisementSource: MEGABoth King Charles III and Kate Middleton were diagnosed with cancer.