My ex cheated on me but i still wnt her.i wnt her to kome bak 2 me.i want her to want me and come back ..help?

im 19 and we have been going out for 2 years and a half.. i wanted to break up because of the fighting.. and the games she use to play with me.. she started crying after i told her i wanted to break up .. so i told her lets go on a break instead because i wanted to be with her and not let her go .. and she goes clubbing and makes out with another guy .. and we broke up ... she acts like she doesnt give a *** anymore .. and i still run after her.. and want her.. but i dunno what to do .. i want her back but .. i want her to realize what she has lost .. i was amazing to her.. i want her back .. what can i do to make her come back to me and chase me