If you had broken up and you are still thinking about her, it only means that you loved this girl very much.If you were not the one to break up with her, then she has played a game and now you have regrets. The clock cannot be turned back again, I suppose. You are pining for her too much and that can be your weakness that she can either exploit or abuse. This means that you might have entered into a symbiosis and her leaving has become life-threatening. That itself might be the reason for the breakup. Girls want a relationship where independence is respected and there is no clingy behavior. You have got to look into this aspect of your personality. Are you becoming too dependent on the girl and therefore demanding, even if it appears that you are protecting her? This is not a welcome feature for a girl to want to maintain this relationship. If she is willfully meeting with your opponents then the message is very clear : she just
does not want you! You must therefore develop yourself to become independent and responsible. Maintain respectful distance. There are three important developments in an individual that creates an autonomous personality: intimacy
, awareness, and spontaneity. Of these, awareness is of great importance: it will help you know yourself internally and to also make you conscious of other people around you. Such a person is able
to meet his needs and that of the other in a balanced manner. You must learn to do this soon. You are still young and have a lot to learn. In fact when you enter college, you will meet many girls and will interact with them. If you resolve
the symbiosis, you will do really well. Meet with a counselor and describe your longings, needs and wants, openly. Take your parents along and let them describe your entire life till now and the counselor will get
an understanding of your plight. Remove everything that is a reminder of this girl and start working on your development. Demonstrate how you will look after yourself and work on doing that. Learn independence skills and do a personality development course too. You are still so young that when this relationship started you were only 15 years: too young to get serious with any one. And never get serious with anyone unless all the compatibility issues and the adjustability is really well understood and established.