Supplemental: Anytime people blame her mental problems on you, calmly explain that she was the one that cheated and broke your heart, that you had to end it, and that you can't be blamed for her actions now. If they can't accept this, then screw them.

A: What exactly is she doing now? Is she stalking you, harassing you, or what? Whatever it is, you and your gf should make log books of everything she does to you two. Note the date and time of each incident, but don't try to provoke her at all (if anything, it would be best to just ignore her). Record a copy of any e-mails, private messages, phone messages, or pictures she sends you. When you feel you have enough evidence, file an official complaint with the police and try to get a restraining order.

B: She's not going to go back to the old her if you're there to help her. You need to get out of her life completely if she's going to get over you. Write a note saying this, and have a friend deliver it for you.

C: Just be with your gf, and remind her that she is the one you love.

Hope this all helps. Good luck!

depends on what she does. I would not try to help her get back to normal cuz if she is totally crazy you are not qualified and she will just manipulate the hell out of you. If she is just calling you both incessantly then just stop answering calls. If you do answer a call say nothing just say good bye and hang up. dont let her get in your heads. Tell your GF not to indulge her either. Block her on FB, dont respond to messages or e-mails. IF you see her in public GTF outta there and do something else. Eventually she will get bored. If she is really persistent could be months. I had a friend go crazy on me and my life was so much easier and I had less stress once I cut off all contact. He would even call me on other friends phones so I would answer it was awful. It took him a good year before all the calls finally stopped (they were less after a few months but I still got the birthday phone call....) And yes I wonder how he is and if he is normal yet but honestly Im happy with how my life turned out and Im better off without the stress.

I totally understand but the best thing you can do is stay away from her and have no communication at ALL. Block her on all social networking sites and make your stuff private. Any e-mails you have get rid of them if you don't really need them. If she harass your girlfriend then file a police report to show her you are serious and not playing. I had a ex who use to tell me she will kill herself if i left. I left her because i was tired of her. I have no contact with her at all and keeping it that way and im married now and happy.