Speaking to CBS Sunday Morning for first time since daughter Katherine's suicide, actor says, "Mental health and cancer... are both diseases, and sometimes with diseases, they are terminal" Martin Short opened up about his daughter’s death by suicide earlier this year for the first time in a new interview. Speaking to CBS Sunday Morning ahead of the release of the Netflix documentary Marty: Life Is Short , the comedian-actor talked about how tragedy marred his childhood, as he lost an older brother and both his parents before he turned 20. “What it developed in me was this muscle of survival and handling grief and a perspective on it,” Short said.…