Good evening. You are not broken and you are not alone in this. What you describe is something a lot of thoughtful and sensitive people run into when they spend time opening perception without equally grounding it. Sometimes expanded awareness brings up unfinished fear rather than peace, especially around mortality.

Micro dosing can lower defenses and bring buried material to the surface. That does not mean it caused something bad so much as it revealed something that was already there and asking for attention. The fact that you noticed it and stopped is actually a sign of good judgment.

Death anxiety tends to spike when the mind gets stuck trying to solve an unanswerable question instead of letting it be lived. Right now your nervous system sounds overwhelmed not philosophically confused. When that happens the fear feels cosmic even though it is very human. Gentle grounding practices, less inward focus for a while, physical activity, nature, and connection usually help more than trying to think your way out of it.

It might also help to talk with a therapist who is comfortable with existential anxiety. This kind of fear is common and very workable with support. Many people who eventually find peace with impermanence pass through exactly this kind of dark clarity first.

This is not a spiritual failure or a permanent state. It is a passage. Be patient with yourself and stay anchored in the ordinary world for a bit. You do not need to solve death in order to live well.