it's sad to hear your story. that is the bad thing to date a person who has ex. i overcome this kind of situation. u try to show her you love her a lot and also try to spend more time with her. tell her how painful you feel when a girl you love so much hurt you like that. you don't have to ask her. you will get her pissed and make her more uncertain. but if you really want to let her go, it is also a good thing. but don't make the decision so fast, you may regret. i hope this helps