You don't have to actually disappear, just not give her "interest" for a month or more. This just means doing what hot girls do to over-eager guys - not initiating contact, answering questions with a single phrase, concentrating on other people etc. etc.
Go after other girls to get your confidence up and after a while of being ignored she might start actually pursuing you like you were pursuing her! If she does, slowly let her do it and then go for it a second time. This worked for me this year.
If she doesn't and you're not going out with anyone else in a month or two of branching out, then you can game her again. Just don't screw it up this time.
If there was a lot of attraction at first, she'll eventually remember that and become nostalgic. When you're getting back in with her, make fun of other guys and even yourself in the past. This will help convince her that you're not like other guys, and that you've changed and become more cool

. But hey you might find someone else you like more than this girl and you should definitely try that for a while. Who knows she might even change her mind quickly and decide she doesn't want to be just friends. Don't push her now, though, it will only turn her off.
Good luck

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