I don't belong

I do not belong to Earth. I try and describe my pain.
You left me with a stain. Oh,anger dripping like rain.
I do not deserve this pain. You left me in the rain.
Oh,poisonous roots in my brain. I cut myself to blame.
You promised a long term relationship,
but you waved goodbye again. I'm suffering from this brain.
 It's too hard to maintain. You see,it's not me to blame.
 I had a hard past,you crave. Please,don't leave me to rot again.
You killed all my braincells. Then you pushed me into a grave.