How do i convince my girlfriend to not be scared of my ?

hi im jared, im black and native american my gf is white and japanese we have been going out for 1yr and 2 months now, then she finally told me she was ready to have , but when she seen my fully erect she said i change my mind i asked why and she told me it was to big, i dont even think its that big its 9 1/2 nches long and about 6 inches round, would be small compared to most stars so its been a while now, and i love her so i dont pressure her about , but come on i am a guy how long can i last with out any advice oh and i heard of enhancement surgery, so is there a such thing a reduction surgery? because i will get that but idk if it exist ty in advance for your answers