who am I?

it's about one of my ex's

When you're having nightmares, i'm the one you would seek.
I am the reason you kept your sanity.
I walked in the shadows and cried at night.
I'm the one you think of under the moonlight.
I am the dream you used to hope will come true.
The wish you made when you we're feeling blue.
I am the one you would run to when you got depressed.
I am the savoroir from the voices that we're getting you stressed.
I am the guy you treasured in the past.
But forgot all about when you parted to fast.
Who am I you ask?...
The very thing you feared to lose, the guy with no mask.
I am the one who saw your momentary laps.
When you sat their i gave your hand a loveing grasp.
I am the guy you loved to kill.
the other guy you used till you got your fill.
And you that tried to use me...you'll soon be all alone.
while i got my homie's making me feel at home.