I saw a television program on hallucinogens recently, I believe it may have been Drugs, Inc. on NatGeo. Part of it covered a man who suffered from debilitating cluster headaches. He was using psilocybin in the form of magic mushrooms that he grew himself as a remedy. Seemed like a very conservative guy that didn't particularly want to take the mushrooms, and he seemed to approach the whole thing with a great sense of dread and anxiety. He seemed to have to literally psych himself up and force himself to take the mushrooms. But in order to keep the cluster headaches away, he needed to do it about once every 2 months. I got the impression that without the relief that the mushrooms provided, he would probably killed himself.
But I felt so sorry for him and the way he was approaching the whole thing. Resisting the experience, and starting trips off with dread and anxiety sounds just awful, like a recipe for a bad trip every time. He could be having one of the best experiences that a human being can have, and he's turning it into one of the worst.
Maybe he could read a few of the psychedelic trip guides and have a better time. There is so much to be learned and so much joy to be revealed.
Relevant information on psilocybin and cluster headaches can be found at ClusterBusters.