Are you aloud to pull a knife if you feel threatened in fla i no u can carry one for a fact though?

I got into in argument at the park I'm 13 bottom story the kids 14 year old sister kept hiting me in the face couse I said stuff to the lil brother as a man I can't hit her back and her brothers 10 and I can't fite a 10 year old he looked 8 so as she's hiting me I pull a knife and point it at her brother and she stops and I said you better *ucking stop hiting me now I'm being charged with aggravated asult with a deadly weapon am I better telling the real story or saying I didn't have one at all witch ones less trouble and if the judge asks why u have a knife I'm gonna say becouse its Dewey park and that's were every one gets jumped that's the truth and it says it can be up to 5 years and 5k in fines