Why did my brother slap me?

We're usually great friends. He was falling asleep while we were playing a split-screen game, so i turned it off. He woke up and started bitching at me. I didn't want to play with him, so this made him very angry i guess. Later he woke up and took my game console in to my room and dropped it on the floor (probably cracked the disk inside) and said he just didn't want it in the living room. I told him to stop and he slapped and pushed me down. He called me disgusting, stupid, and rude. He blames it all on that time of the month but i didn't even do anything.

He's never done this in years. He's 23, i'm 16, what can i do? My dad left us. My mother won't listen, i don't seem to be her favorite child xP

I just feel so screwed up because my brother was like the only person ive had in my life. He was like my parent and it hurts being called worthless by your only friend. I really don't know what i'm asking snymore, just give me some advice? Sorry it's so long =)