My dad is way to over protective any help ?

my dad hates me having boy friends im 11 and i have had them since i was like 9 and now i have found one and he is 2 years older than me and my dad will not let me see him he does not even know who my boy friend is , my boy friend has given up everything for me his best friends he gets bullied for being with some one two years younger but yet he's still going out with me but my dad doesn't want me seeing him no more other wise there will be a really big argument he sed , and he threatens me but i really like this boy and he's done everything for me i don't want to loose him . my dad is being stubborn and won't let me even talk to him maturely about it. Im not even aloud to wear a skirt for high school and i really want to im not sure if i even want to live with him anymore , help does anyone know what i can say to him or do ?