Debra Messing and cast members of NBC’s canceled “Smash” drowned their sorrows at BlackBerry’s Gersh Agency party at Catch. While Messing refused to speak to us, her agent said, “She’s sad. It’s a bummer. She loved it, and she loved the people she worked with.” Megan Hilty told us she’s also upset, but “There’s no point dwelling on it.” She added, “Fans are very upset. The tweets are just endless.” Hilty’s looking forward to her next project and told us she wants to do something funny, but just wants to keep working — “I’m not too picky.” The musical show, however, is expected to go out on a high note May 26 with a two-hour finale and a musical number written by Marc Shaiman and Scott Wittman. Guest stars on the show have included Liza Minnelli, Bernadette Peters and The Post’s Michael Riedel.