I hope you find the resolution you are seeking DepressedFiance...whatever that means for you. If you do decide to have further dialogue with your gf (even if not to reunite) here are a few communication tips which you may find useful:

- provided you are both willing and able to remain calm, it is best to talk in person (texting or phone calls don't always go well when there's tension...no facial cues etc)

- try sitting next to her rather than across from her...that signals that you are communicating with her rather than accusing or interrogating (nobody likes being interrogated, right? Regardless of the situation)

- keep your body language open rather than guarded or oppositional

- use non-judgmental language such as: "I feel hurt that this happened and I am confused about x, y, or z. Would you please explain it to me from your point of view?"
(think of a time when you communicated with anyone out of strong emotion...it probably didn't go so well, right?)
Even though you are hurt, avoid saying things like "it's your fault because..." or "I hate when you..." etc Respect her boundaries. She's in her mind with her perceptions and experiences and you are in yours. If she doesn't agree with you or doesn't say what you hope to hear, just take a step back and acknowledge that she has the right to feel however she feels even if you don't agree.

If in-person communication does not go well, just calmly end the talk before things escalate, leave, and later write her a letter when you are not feeling heated. A letter would at least give you the chance to convey your thoughts and feelings which could be cathartic. Though if she doesn't respond at all or not in the way you'd like, again that is her right. Just leave her be.

Remember that all feelings are temporary. You could be feeling deeply hurt, angry, or hugely disappointed now but these feelings will not last forever. And if you do decide that the relationship cannot be salvaged, then allow yourself the time and space to grieve the loss of the hopes and dreams you had for a future with your ex-gf.

When my prior relationships ended, I made it a point whenever possible to end things on peaceful terms. That does not have to mean forgetting or instant forgiveness...but to simply step outside of the confusion and pain long enough to acknowledge the other person's humanity by saying something like: "I wish you all the best for the future. Take care of yourself."

You may look back later in life and find that these sad events actually led you down a path that wound up being much happier than you could have even imagined. I know that has happened in my life several times.

Sorry you are going through this pain, Depressed Fiance. Breathe slowly and deeply and take good care of yourself.