I may be swimming against the current but I think there needs to be forgiveness and moving forward on both of your parts. You may have had unrealistic expectations but she helped build them up.
Neither of you have clean hands in this case. Both made choices that were ill-advised. You should not have asked for the promise even if it was what you thought she wanted at the time. Nor should you have put such a high emphasis on it after she broke up with her ex. She should not have made the promise or lied about her actions. She should have either told the truth or said it was not your business.
You are a young couple and this is just one lesson in learning to end a conflict and move forward. I do think it is more about her lying for so long that has been more damaging than expectations of 'first times'. You knew who she was dating and his reputation. Some part of you probably already knew before she said anything. However, the lying does lead to thoughts of what else has she lied about and can you trust her in the future. I think it all depends on how both of you work to resolve this issue and rebuild the trust on both sides.
I think I see the glimmer of a young man who is allowing the shock of learning that his girlfriend had been lying to him for a year to wear off. A young man who is learning that expectations can adapt to reality. I think I prefer to give that young man a chance to learn and grow.
She must see something in you which may not come across in this thread. Something that she thinks is worthy of her, her time, and her energy. I will guess that she sees a caring and understanding person that may not be as noticeable here. Can you be that person for her? Are you willing to try because you know it is the right thing to do? If so, good luck.
