How could this happen to me?

I can't remember how

I can't remember why
I'm lying here tonight
and I can't stand the pain
and I can't make it go away

I try to make a sound but no one hears me
I'm slipping off the edge
I'm hanging by a thread
I wanna start this over again

so I try to hold on to a time when nothing matters
and I can't explain what happened 

and I can't erase the things that I've done

how could this happen to me
I made my mistakes
got nowhere to run

and life goes on 

as I'm fading away
I'm sick of this life
I just wanna scream
how could this happen to me?