Killing me

What is this i hold in my hand
its a sharp and shiny blade
and guess what it can do
it can cut stab and scar
but what if i hurt you
would you run away
but why
you don't have my nightmares
and you don't feel my pain
why should this hurt you
why should you be afraid
you don't watch the blood
and you don't hide the scars
why should this be affecting you
your not supposed to know
its your fault that you do
you should have stayed away
you should never have gotten close to me
now my hurting is causing you pain
and that is killing me