Why do i still have feelings for him?

I'm 15, High School had been rough with me. I met this boy, I always thought that he's the cutest funniest boy ever. But he did my dirty. Very dirty. He only dated me for Valentine's day, and I was fresh meat cause I was a new girl at the school at that time. And broke up with my after my birthday. Which it was in early March. Then he told everybody that I did sexual acts to him. I hate him. But I still want him, i know it unhealthy for me but. I know he must be a sweet guy deep down inside.