Little brother problems

So I'm babysitting my 8year old brother (I'm 16) over the summer and he just pushed me and hit me and threw things at me. I have never hit him or done anything to hurt him and I don't know where he has seen this behavior before. After he did all of this I started crying and then he wanted to hug me but I didn't want to be near him. I don't know what to do because he never listens to me if I tell him to go to time out (he usually crosses his arms and says no). I don't want to disappoint my parents but this is really taking a toll on me. I feel like he hates me and like I'm a terrible big sister.. Help?