Laurad, you could gain some weight. Your "masculine" looks are actually the bones.
On the other hand, you could take this "andro"thang, and run with it.
For example, you could wear a tuxedo to some party! That would throw so many people off, I can imagine their reactions!
Funny.
And then you could do all sorts of gender mixing, like, some days extremely femenine and other days extemely masculine and in between and you could train your voice to sound like a guy at will so that when people say "ma'am" you tell them "I'm A Sir!" and when they do call you sir, you tell them "I'm a lady~" and then if people ask your gender just throw a coin and say "heads, today I'm guy!" and then you'll laugh at them poor people victims of their own ignorance.
*Breathes*
...Or you could not. Whatever, it's your life.
Oh, another thing, if people give you trouble about you looking like a man, punch them in the nose. And then tell them "how's that for a girl!?" Or whatever oneliner you can throw there. Just make it cool.