How do i get my dad to accept the fact that im ?

im . i finally told my mom and dad. my mom doesnt have a single problem in fact she helped me find the girl im with right now...ily baby..anyways my dad said i cant have a gf bc im not and no matter how many times i tell him that i am.he doesnt listen.he keeps saying no your not. how do i tell him that he has to accept me for me and not turn his back on me?