Question about assault causing bodily harm in Canada?

ok so someone stole sixty dollars from me so me and freind went to confront him peacefully he even admitted to stealing it and said he through it away because he was scared we would find him with it when we confronted him he grabbed my freind by the shirt and held his fist up threatingly my freind told me to put his phone on the grass in case this kid hits him and he has to fight back so put it on the grass behind the kid who stole.....he then elbowed me in the stomach and i fought back i only ht him 3 times before the fight was over and he had a broken nose now hes charging me for assault causing bodily harm but for that chargen to work it has to be "grevious bodily harm" which i dont think a broken nose is and i was defending myself in the first place can he actaully successfully charge me for this and if so what would i have to pay?