Approaches
I am sorry that you're experiencing PTSD symptoms. Have you been formally diagnosed, or are you self-diagnosing? What other treatments have you tried?
Any chemical interruption is temporary - this means plants, minerals, prescribed medications, weed, etc. They all only interrupt the PTSD cycles and do not "cure" this disorder.
There are many, many approaches to treating PTSD, but the first and foremost assistance to anyone dealing with it is to accept that it will be managed, not "cured."
PTSD is when the brain reacts to certain stimuli that include sight, sound, aromas, colors, music, textures, foods, words - everything and anything can start a PTSD episode. Knowing this, steps can be taken, but they must be taken by the individual and the approach must be with the understanding that management is the goal. Every day, there may be new "triggers," and that's the next prong of management.
Engaging in intensive counseling therapy with a mature, licensed professional who specializes in trauma, PTSD, and whatever else has contributed to anyone's conditions is an imperative. A licensed specialist can help guide their client to techniques that will help them calm themselves, focus, and redirect their thinking processes. It takes time, courage, and diligence.
Taking herbal hallucinogenics may not be the wisest option, particularly in consideration of how PTSD episodes unfold, and unravel the individual's thinking. I would go as far to say that it could result in catastrophe to do this without the guidance of a professional.
Best wishes to you on this journey. It isn't easy, it isn't instant, and it is a lifelong management effort.