When you love someone and she doesn’t love you back

She was my neighbor, i was 19 she was 17, i was young and naive, she noticed me, i used to find her beautiful and i was hopelessly in love with her ,I used to deliberately wait at the bus stop for her ,I used to pray so that we could be on the same bus . Whenever i saw her my heart used to do hairsprings I enjoyed every moment i got with her, i used to think about her 24 hrs and still I couldn't get enough of her. Whenever her pesky sister used to interrupt us in mid conversation I had to control a terrible urge to wring her neck. She used to do it deliberately and i absolutely hated it. I thought that she knew that I loved her and it will take her time to be free with me as the stifling presence of her dad and sis used to be a constant feature of our meetings so i started missing school just to talk to her, my grades dropped and my troubles at home multiplied but a strange attraction for her kept me going. At times she ignored me but I didn't mind it as whenever she needed someone I was always there. I gave her my shoulder to lean on when all she needed was a hand but she didn't love me she showed this in the most cruel way she used to bitch about me and my family with her friends when I came to know that I didn't feel angry i was heartbroken as that was the way I loved her, but i took this in my stride and kept on a facade of normalcy I didn't act like a loser, I was a survivor who learn the hard way that sometimes you can love some people who are totally undeserving of your heart. I still don't know that a 17 year old can differentiate between infatuation or the love of her life but I know one thing that my feelings for her were true and I can't blame her for not loving me all I can do is wait but if I feel that I was wronged is that justified, should I make her pay for her betrayal of my trust why shouldn't I make life hell for her but what will I achieve?