Reason to live (Ellie x OC/Female reader)

This story is fanfiction to the game The Last Of Us (big surprise). Even if you don't know the game, I'm sure you'll be perfectly fine if you read the last chapter: Names, nicknames and explonation before you start reading.

"Join old smuggler on his journey with a little girl, to find a cure for the Cordyceps fungi virus. On their way they meet a lot of interesting people and get to know each other better.

Andrea thought she's lost her best friend because of what she did. But as it turns out Ellie is more then alive, she now has a purpose. She has to save humanity itself. Will Andrea be there for her this time? Or will she leave her and run again? Does she even have a reason to stay?"

So in order to keep you hanging a little, I'm just going to say that this story is different from the game. But you're gonna find that one out on your own, won't you?