Aww its ok as long as you know u are a girl then everyone else can shut their front door.. And for YOU to feel more like a girl then just use more feminine clothes and just wear some makeup but you don't really have to. For the key is to believe it of course and act it.
Highlight your feminine features and mask your masculine features. For example, use lip liner to make your lips bigger and fuller. Pluck your eyebrows and keep them thin (just remember not to pluck away at your entire eyebrow). Make your eyes look bigger by putting white eyeliner on your waterline. Wear your hair in a way that is feminine, but still shows off your facial structure.
Try dressing up a little fancy. Brush your hair out, maybe curl it. A nice skirt and colored leggings or some slim jeans- not too tight, or it'll hurt- looks good, too. Maybe wear a blouse with one of those little dress jackets that ends halfway up the shirt. You could also try visiting a cosmetologist in the makeup section of the mall or something to get some advice on the makeup that works best for you.