Hi Thesplitpersonality710, I would like to first say that I enjoyed your story very much. I liked how you transitioned back and forth: from the events in the beginning to the present and the past. The relationship between the character and Sarah was believable and it was nice to see how it developed. It piqued my interest to uncover the events of the story to the end.
I will admit, and please do not take offense, but I felt that adding the other people at the end took away from the story a little. You can keep it in obviously if you like, but I think if you left the main character's fate to Sarah entirely, it would fit better. This again is an opinion of one writer to another. I like the story nonetheless.
Moving on now...I did see a few minor grammatical errors I caught that I thought you should address:
+Most of Sarah’s hair was removed from her scalp, which left her bumpy head *bold* and burnt.
+During the *ending* of August Sarah and I decided to go to a waterpark by ourselves. It was around nighttime when we were arriving close home.
+I had a *tang-top* on as I drove, which showed off the muscle tone of my body.
+*I* huge chunk of my memory felt fuzzy and out of place.
+Roger and I were inside my room when my *parents outside* with the cops.
>parents were outside
+They were *huger* crybabies than I was.
+“Jesus Christ, Andrew, a CAR!” Dom snapped at me. We were driving on the grass field that followed the paved road. I yelp quietly, and steered the vehicle back to the road. My heart pumped faster, and my nerves twitched. “You gotta pay attention to the road. Almost got ourselves killed, dude.”
>Since they were driving in the grass, did you mean?: "my car?" "or watch the road?" ...maybe?
+I shared Sarah *and* icy look, and she returned my gesture with a cute wink.
+At first I played *prank* on some people that I didn’t really like.
+cost me my life, basically, but as long as you lived I was happy. * “ *I had to fake my death, obviously. The whole time there was a fake copy of me inside the casket.
>Remove double-quote since it's with-in the dialogue.
+The fire enclosing us disappeared with the yowling *wing*.
+Multiple hands snatched my limbs and *bodies*, and I started screaming for my life.