((( freewill )))

That sounds so frightening. I'm sorry that happened to you. I have gone through similar eperiences.

It sounds like a body memory/response to the previous trauma, but I am no expert. My T always says "the body remembers."

There are quite a few books out there on this subject that may help you understand how the chemicals in your brain actually change and respond to the reminder of the trauma etc.

The Trauma Spectrum: Hidden Wounds and Human Resiliency by Robert C. Scaer

The Body Remembers: The Psychophysiology of Trauma and Trauma Treatment by Babette Rothschild

Waking the Tiger : Healing Trauma : The Innate Capacity to Transform Overwhelming Experiences by Peter A. Levine

Healing Trauma: A Pioneering Program for Restoring the Wisdom of Your Body by Peter A. Levine

The Body Remembers Casebook: Unifying Methods and Models in the Treatment of Trauma and PTSD by Babette Rothschild