How do I move on?

I went to this family thing in another country, I met so many of relatives and we had fun and all that. But I met this girl there, too (she was my cousin's wife's best friend, so not a relative). She was so amazing and beautiful and we just instantly clicked. On the first night we literally just sat and talked for hours, even long after the family event there ended and she hugged me before she left. I knew there was something, but I was a bit hesitant since she was 29, and I'm 22. On the second night, we went out together and we danced in a park somewhere, I loved seeing her smile. She kissed me on the cheek before she left that night. On the third day, we didn't see or hear from each other, I was panicking because I had no way of contacting her and I was leaving on the next day. But, she called me that evening (she had asked around for my number), and told me to come to her house because she wanted to say a proper goodbye. I went to her house, some stuff happened, and I fell asleep at her house. The next morning, she drove me to the airport, we said our goodbyes and she looked so sad and it really hurt to look back at her as I left, but I did. We both agreed that it would be best if we didn't pursue our "thing" any longer, and that was that.
It's been a week now, and I just can't get her smile and her beautiful voice out of my head. I don't know how to move on from this.
How do I move on?
Add Opinion