Shirin Ahmadi smiling in front of Cathedral of Santiago de Compostela, the endpoint of the Camino de Santiago pilgrimage. Shirin Ahmadi

After the 31-year-old author fell and sustained a concussion, it prompted her to reevaluate her life.

So, she embarked on the Camino pilgrimage in Spain to overcome her anxiety and find a sense of peace.

"Walking didn't fix me. It just made me finally stop running."

Darkness. And then a slow ringing, swelling like the sound of a slowly approaching train. Then came the throbbing—above my ears, on my forehead, all over my thoroughly jostled head.

Blood was pooled into a slick glob on the brown marble floor, like a Rorschach test with no answer. My nose throbbed, likely the source of the bleeding. I could barely see. I blinked, confused, hoping this was all just a horrific dream.

Where the hell was I? What happened?

I remember my clock lit up, showing it was 4 a.m., when I awoke and urgently needed to use the bathroom.…