who am i?

i'm not so sure who i am anymore. i've changed myself so many times now. sometimes to fit in, others so i wont fit in, so he'll like me more, so i feel more invisable.
honestly, i have no idea who i am, or if i like the person i am right now.
how long does it take to work out who you are?
honeslty, half the time i feel so i guess you could call it happy, that i think i can fly, or cars will go throught me because they are less real than me. the other half i spend extremly depressed and suicidal. i feel like i am nothing but emotions anymore... like there is no one here...