I can certainly understand where you are at. I am 42 now and when George Carlin died it was kind of a shock to me. George was one of those guys that in my mind was gonna live forever.. And he did! Sounds strange but when I listen to a recording of his shows it's like he's still here.

Maybe you can watch some of Robins movies or comedy routines. It might feel bitter at first but after a while MAYBE the sadness will fall away and the good feelings will return. Sort of like exposure therapy..