I NEED SOME GOOD ADVICE AND BIG TIME HELp!!!!!!!?

okay, there's this girl i like at school and i like her a lot. She knows that i like her along with the whole entire school. im positive i had a chance at the start of the year, but now its gone way down and she doesnt like me AT ALL. she thinks im a stalker cause i go wherever she goes and never talk to her cause i can never figure out what to say (we have exactly the same friends and we know each other pretty well) so now im like way down in the hole and i like her too much to let her go. if you have an idea for like a "comeback" (like in sports when you're down by 2 touchdowns in the fourth quarter) please list that. im a freshman in highschool so the "comeback" idea you have can last a couple years or sumtin. dont list negative comments cause they put my self esteem down, lol. again, she doesnt really like me, and i want to literally grab her attention towards me! i need ur help so plz help ME!!!!!!! ANYTHING WOULD BE GREAT