i have been in a similar situation my self, my ex boyfriend and i had a fight, well i kept hitting him, he retaliated, but he did try to do the right thing and walk away, he was charged because of my mum ringing the polcice :@, he was charged with section 20gbh, due to me having a broken wrist, but i have managed to prove that he didnt break it, i broke it before we even started argueing, ( i fell out of a taxi), anyway the cps have agreed to drop the charges to section 39 common assualt, but there still pursueing that :/ iv tried asking the cps not to go ahead but as i have found out there is nothing i can do and they will continue it until the end, according to them its in the publics interest,so im sorry to say but yes it will definatley to trial at the crown court,
hope it all turns out ok for you though :)