Who am I to you?

Tell me..who am i for you..?

I'm so confused...
I can understand..
when you're go away from me..
I know,i make some mistake..
and you think,,it's better for you..
To go away from me..
Leave me alone..
And make me cry..
In the night..
when I close my eyes..
I always thinking about you.,
what you do..?where you now..?
When I'm alone..
I always listening the song..
that we sing together..
Like when we are in relationship....
Now I wanna now..?
who am i..?
Please,tell me
WHO AM I TO YOU..?