How can I hate her and not like her anymore?

Hi, I'm 16 and have been in love with a girl in my class since fifth grade. I don't know if it's love or like, but she's always on my mind in the morning and at night at school. I keep trying to talk to her, to get her attention, to text her, but I don't want a relationship, which is why I don't text her much and I don't do anything with her. That's because she's been my boyfriend for a long time and I know if I text her a lot or say that I love her, she'll mean it and tell her friends. But it's really not like, it's sweet, I don't want this love and I try to just hate her and not like her, but she keeps going through my head.