Yes let her go. sometimes just because it seems good dosent mean that its good for you. You have done the right thing, dont let her or anyone for that matter to play with your emotions. The best thing i think is to not call her or answer her calls for a while. If you see her say hi but move quickly at least for a little while. You are right sometimes it takes people making their own mistakes to grow up. The best of luck and you will be fine, you seem like a great guy.