Chadwick Boseman’s widow is speaking about the “most challenging two years” of her life following the “Black Panther” star’s death, and says she feels grateful for the short time they had together. Boseman, who died in August 2020 at age 43 after a private 4-year battle with colon cancer, “was an artist, and he was a leader and he was a king,” Simone Ledward told “Good Morning America” on Tuesday’s episode. “Some days I’m doing worse than I’m really willing to acknowledge. And other days I’m doing better than I feel comfortable admitting,” she said. “I know that Chad would never want me to mak…