Kate Beckinsale shared a heartbreaking message about navigating PTSD, comparing it to living in “hell.” The “Pearl Harbor” actress said in an Instagram video Wednesday that people who “have seen or experienced levels of horror, terror, violence” cannot escape their traumas, but they should be recognized as “heroes.” “A lot of those people become incredibly good at masking it,” Beckinsale, 53, said. “And it’s sad because they become so good that they get no grace whatsoever.” Beckinsale, whose mom and stepfather died within the last two and half years, explained that while people with PTSD go about their everyday lives, “they don’t sleep…