Well take this as an advice from someone who had been dealing with that kind of fucked up thing too:
- Erase everything that reminds you of her. (ie phone number, every photo, etc)
- Remove her from your social networking sites and apps.
- AVOID PLACES WHERE SHE GOES (this might be harsh, but you have to be strong)
- Let your feelings flow out. (cry if you need, listen to songs about breakups)
- And last but not least move on and try to find another girl, it might take some time until you find the right one, but trust me you eventually will. @gbazsa