Classic Poem

I have too happy been
Some sad Fate envies me.
An arrow she, unseen,
Has fitted to her bow,
And smiling grim, I know,
Let the drawn shaft leap free.

Deep in my side it pierced:
With sudden pain I shook,
And gazed around, the accurst
Perfidious foe to espy.
Lo, only thou art nigh,
With sweet and troubled look!