I got sucker punched and im in trouble for disorderly conduct? help?

my older cousin came to my house and tried to intervene on a small argument with my brother. then I was talking to my brother afterwards and all of a sudden he sucker punches me with his keyes in his hand and knocks my front tooth out. then he tried running to his car but I got a hold of him and hit him a few times in the face. then he gets away and hides behind a tree and calls the police on me and im the one being accused of disorderly conduct? I have court soon someone please help