A confessional-style comic, Chris Gethard is unafraid to mine his past. He talks about cramming the entire set of his TV show, “The Chris Gethard Show,” into the back of his car’s trunk, and how he pulls off hour-long phone calls with strangers every week on his podcast, “Beautiful Stories from Anonymous People.” Amidst a tumultuous cultural change, Gethard also discusses the current state of comedy and his HBO special, “Career Suicide,” which chronicles his history with depression and anxiety.