Any criticism would be greatly appreciated, as English is my second language :

Dear T,
You are not my mother.
You did not create me and your body did not give life to mine.
You did not raise me up; you have not fed me, nor were you there when the baby I once was have become the person I am today.
But you are nourishing my soul
You are making me grow
There are many things that you give me, but two of them stand out for me – your love and your emotional presence. You are present with me like no one in my life has ever been before, and that means the world to me.
You are helping the person I am today to become the person I will be tomorrow, and thus you are raising me up.
With your love, you are helping me become, and thus you are creating new life in me.
And so, despite the fact that I am not your offspring,
Inside my heart
You are my mother.
I am so lucky to have you be part of my life, and I am forever grateful.
Much love,
Vaffla