Hopefully, the police will review it and drop it, if not it'll be forwarded to the CPS who will review it and drop it. If not and it goes to court, then just essentially tell the truth laying it on thick how you were afraid he was going to escalate to hitting you and lashed out on an instinct and hope they buy that, plus the effect it's had on you since ( the shame at being arrested, job worries etc, relationship issues). Thing to remember you can never look too humble, respectable, contrite and scared when you attend court, so suit, softly spoken, good manners when you address the bench and look like you wouldn't say boo to a goose. that's a worse case scenario- I'd imagine the CPS will drop it myself.