Translation of oleada

I fell asleep but woke up in the middle of the night. My stomach turned upside down and I could not hold myself anymore. I needed to vomit and ran to the bathroom. This occurred three times.
I would like to mention the conflict on the balkan, which has been going on for centuries. Both fought for religion and for land. During the fighting the hatred grew and stereotypes were built.
She was a very cute twenty six year old woman from the area, had a perfect English and could be understood well. She told us to put on good shoes and we started walking towards the valley.