How to stop being too nice?

i am in love with a girl, but i've already confessed my feelings and she said she doesn't feel the same.

Still, we got closer and closer until we became best friends. I hoped she would change her mind, but she still doesn't feel the same way. I am very open about my feelings and she doesn't judge me for it, she is actually very nice. Last time she said she thinks there is a chance to be her first love (she never dated anyone), but I'd need to "win her heart".

She even said I'm the only one she can open up to. We talk almost every day (she texts me more than I text her) and she cares about me - but it seems nothing I do works to make her see me more than bff.

How to stop being too nice and make her really feel attracted to me?

How to stop being too nice?
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