Snape and Lily

Severus and lily.
This is in no way me trying to rewrite what Rowling did, cause it's awesome, I just wanted to write something that showed Severus and Lily getting together. So here is my attempt, hope someone out there likes it. 

He who must not be named stepped over James' body and stalked towards the door, where on the other side Lily Potter was trying to pile items against it. A futile attempt to protect herself and her infant son. She rushed over and put Harry in his crib. Panic stretched across her face, Harry couldn't die, he just couldn't. A flash and a bang and Lily knew He had blown...

After a short time from the battle Harry insisted to go to the head masters office alone. Once he was in the office he went straight to Professor Snape’s portrait.

Harry: "Hello Professor"
Snape: "Oh, Mr. Potter to what do I owe the pleasure of your presence today?"
Harry: "I have brought something I recently found in my vault at Gringotts that was addressed to you."
Snape: "Me? What would possibly be addressed to me in your vault Mr. Potter?"
Harry: "It’s a letter sir, from my mother I recognized the hand writing from a letter I found at Sirius’ place."
Snape: "Okay, Mr. Potter please read...

Suddenly, he saw very strong light. He didn't understand what's going on. When he appeared in a dark room, illuminated by the moonlight, his thoughts confused. Suddenly, next to the window he saw what caused him to speak.
- L...lily? - he stared at her like a kid in a candy store's window.
Girl, who stood at the window, turned to him. Severus saw her long fiery hair and no longer had any doubts. His Lily. They were slowly catching on to the next one.
- Yes, Severus, that's me, - whispered.
He instantly ran to her and hugged her.
- But ... How? How can this happen? - his voice was shaky, tears...