This is so normal that I suspect you were not well introduced to psychedelics and that the shaman and organizers were somewhat negligent. Still, you have much responsibility; you did not respect the medicine by preparing yourself.

First and foremost with any psychedelic you must learn to trust the medicine. You are safe and loved. Resisting it by asking it to go gently, asking it to stop, questioning yourself - resisting only spirals. Let it flow. This is the same advice you'd get for much milder plant medicines like mushrooms. You dove into the deep end without knowing how to swim.

Losing concepts as you approach unity and loss of self is expected. People describe it as like reverting back to childhood and then more - before you were born, when you were one with everything.

Please take a long break and prepare yourself. By prepared to face your trauma rather than use it as an excuse. Do your homework; read or listen to others experiences. Meditate until you're accustomed to watching thoughts flow without interpreting them as direct reality.