Help please...

[Eblis91]

Hi, i`m new on this forum, and i registered 'cause i need help.Well here is my story: (excuse my not perfected english communication, I`m from a country where english isn't a common language..)
I'm final year of high school (19 years old) and i met a girl that's going to same school as i do like 3 years ago.. Since the first time i saw her i kinda felt that she is a total match to me and a soul mate (later it turned out that we have lots of things in common (sport, music, books, romantic view...). I didn't do anything for a while after that, 'cause i had some obligations but round a month later i decided to take some action. Unfortunately I found that she has a 1 year long relationship with some guy..
I know its a bit egocentric and arrogant to say nice things about yourself and your character but this is what i think of me:
I`m a person who has moral principles and don't want to break them.. I`m always trying to deal with others the way i`d like them to deal with me. Reason i`m saying this is 'cause i did not want to mess with her relationship and put her in a position where she would have to chit on her boyfriend, or where i would have to ''steal'' someone others girlfriend...
So during the time she was (and still is) in a relationship, i tried to connect with her in any way, mostly to make a friendship or any kind of way where i would be close to her. I did not point out to her that i have other interests than friendship but i believe that she is awear that i like her so much (she had various ways to find it out (mutual friends, my behavior and many many others)). I did not lose hope, 'cause i seen her many times smiling to me and observing me in school (school yard, school hallway...) I decided to wait for her to break up with her boyfriend... In a disco she came and danced a couple of minutes with me.
I started to love to go to school (WTF?o.O) because its an opportunity to see her, and be in the same place where she is. Еvery morning, a new school day is a blessing, and i started hating weekends...
In the meantime (3 years) i got many awards for being the best student, best basketball player, many other competition awards and things.. Dispite this, i think of myself that i`m a total failure.. I don't think of nothing else except of her, whole day, every day.. Often i get into some kind of a depression state and think of suicide (i am sure i`m not a suicidal person, or hadn't been ever since). I've turned down (if that's the phrase) many girls in between. I think that i`m total in love with her and i really don't know what to do.
I could probably go on like this for much more time but the thing is, i got 7 more days before it is finished (college is on the way). So after this 7 days, i will never see her again if i don't do something. We shall split on the other sides of world most probably and i wont hear of her anymore.. She still has a boyfriend (the same one), i am still an asshole, and she is still flirting or whatever she is doing with me..
Last few weeks i made a decision to tell her what i really feel about her but it is really hard to do in a school hallway or a schoolyard when there are many of our friends and other circumstances that are making me back up. Time is running out so please help.
I am not sure if this is the right forum or forum part to ask people for help, but in case it is, thank you for your interests and patience with reading this help request, and thank you even more if You`re about to try to answer and help me somehow..:S
Edited: Wops i just noticed that my state flag. I didn't know what was the abbreviation for Serbia.. heh;p