She kept him 'in suspense' [=waiting anxiously] for two whole days before she agreed to marry him.
I don't know who won and 'the suspense is killing me'. [=I am very anxious to know who won]
The 'suspense' builds as the story progresses.
(..) - Come on, Santa's Little Helper! - Come on, dog! Go, man, go! And with a lock on last place, it's Santa's Little Helper. - Don't worry, Dad. Maybe this is just for suspense before the miracle happens. - Come on, you stupid dog! Come on! - Go, go! - Run! Run! - Run, run! Come on, get that rabbit! (..)1989 TvShow: The Simpsons Title: Simpsons Roasting on an Open Fire Season: 1 Episode 1