Two in One

You who are two?
But one in the same
You are he
And he is you
One is blue
The other is green
You don’t belong here
You want me here
I am all I need to be
You are nothing you want to be
Always fighting
Always sharing
Why do you fight with yourself?
You are not me
No, I am what you want to be
Father you scream
Mother you cry
Who am I?
Or am I a we?