Right after Christmas, my engagement has been 'officially' called off (I would argue that the damage was done when we didn't get married in August and I moved out in September), and I've done by best to start moving on. I've enrolled in Master's classes, have met some new women, and gone out on several casual dates. My ex-fiancee' and I have continued to stay in touch.
When I told her I'd met someone whose company I enjoy, she became nearly hysterical, and called me shortly after midnight of the same evening, masturbating while on the phone. I have tried to block her email, but was unsuccessful, though I have since discovered a means to delete her emails when they arrive. I have fed this fire I realize, by trying to be nice, and tell her that I will take from this relationship positive elements, and will look back fondly on our time together. I've also told her I wish things could have been different.
She has now called me to tell me she has met someone else and that she needs me to respect that. I told her I would, and wished her well. Since then two days have passed, and she's called me twice, once not leaving a message, the second time to tell me she needed an address to mail the remainder of my things (which is curious, as she's mailed things to my house before, and this is the third of fourth time she's told me she had the 'rest' of my things to give back). She then instant- messaged me last night, again requesting an address.
Through all this, I have failed to mention she was in an auto accident in January. Though she was not at fault, she was still charged with DUI, as she had been drinking, and was driving her 5 year old son home at the time of the accident. After receiving particularly virulent emails this morning, I informed her that I was blocking her home email address at MY home, and deleting her emails here at work before I ever read them. She has moved to a different part of town, and I'm hoping that the distance and her fresh start will enable us to really be done with this. Tell me I'm enabling this by answering her emails and wishing her well. Honestly, I just want to be done with this at this point.
How to close the book
You say you want to close the book but as you yourself pointed out you are continuing to have contact with her. Are you sure that you want no contact with her? Your actions say otherwise. Are you sure that you aren't hoping to get back with her on some level? Do you feel guilty to have broken off the wedding, and is maintaining contact a way of atoning for your guilt? Are you trying to let her down easy by offering her crumbs of friendship? Is it possible that your unconscious still hopes that you can work out whatever problems broke you up?
Don't forget that most of us fall for lovers who remind us of our parents, who often let us down. We choose carbon copies of our parents so that we can relive and in the process heal our childhood traumas. It is usually hard to let go of a lover precisely because doing so means letting go of the hope of ever healing the childhood wound. This may explain why you are finding it hard to close the book on her--because you don't want to close the book on yourself and your chance of healing.
Clearly some piece of your unconscious mind hopes to accomplish something by staying in touch. If unfinished childhood business isn't fueling your continued contact, then you have to assume that staying in touch is your way of doing what all humans do: seeking pleasure and avoiding pain. In your mind you must be thinking that maintaining contact will help you to escape a painful feeling (guilt, shame, etc. ) or bring you a reward (make you feel better about yourself because you acted like a good guy).
If you can figure out what feeling you are trying to escape and/or what pleasure or positive stroke you are trying to obtain by staying in touch, then you will be in a much better position to deal with and resolve the issue directly.