Depends on what was horrible, terrible, or whatever.

He is talking about finding a dead body in his basement, with a part of the body missing. Just to give you a little bit of context. (sorry I didn't write that earlier - I'm so emerged in the translation, it didn't occur to me that you might need more contextual infos)

kommt drauf an: wenn's eine Erzählung eines abgeschlossenen Erlebnisses ist, dann muss es "was so terrible" heissen.
"It's been so terrible" bedeutet, dass der Schrecken immer noch anhält.

Der Schrecken hält noch an. Aber "terrible" statt "horrible"?? Was sind hier die Nuancen? Any native speakers?