It sounds like you are infatuated and you need something to occupy your mind so you stop thinking about her. Try to spend more time with your friends, do something fun, go out and meet new people, work out, pick up a sport, build up your self esteem. You might think that she's the only person in the world right now, the one and only. The truth is, there are many girls like her and once you infatuation runs out of steam you will be able to see that more clearly.
Don't cry, don't regret and don't blame
Weak find the whip, willing find freedom
Towards the sun, carry your name
In warm hands you are given
Ask the wind for the way
Uncertainty's gone, your path will unravel
Accept all as it is and do not blame
God or the Devil
~Born to Live - Mavrik~