A two edged sword

A two edged sword, freshly made,
never before tainted, a perfect blade.
She kept it on her at all time,
when I was hers and she was mine. 

Maybe she had not planned to use it,
but things can happen to make her lose it 

and one late night it left it's sheath,
it sliced through my soul from top to beneath.
Oh how I wish that this were true,
so I'd be dead and not thinking of you,
cuz never deeper has any sword cut,
then those four words, "I love you.. But...."