it sounds like a significant experience to me. i vote for sharing it with your therapist. it sounds really traumatic to me. i had a similar experience as a child (although i reacted differently) and its a story i remember quite vividly! it ended with me at a park on the swings and a cop car pulling up and my mother springing out of the car and running towards me! (they thought i was kidnapped or something)

what would be the downside of sharing this info?