http://entheoguide.net/wiki/Main_Page
http://www.psychedelicpsychotherapy.com/content.php?122-jour...
In addition, here are some guides for dealing with difficult experiences:
http://www.erowid.org/psychoactives/faqs/psychedelic_crisis_...
http://www.maps.org/videos/source4/video9.html
And of course all the information on Erowid for each substance is key. Psilocybin isn't especially dangerous, but as you said if you do it wrong you can definitely end up with anxiety/depression that lasts a year or two.
I used to think that all educated adults had read the same books about history I had, but I was surprised when I was in law school that my professor of criminal law and criminal procedure had never heard about why drug laws in east Asia and southeast Asia are very harsh. The painful experience of China after defeat in the Opium Wars means that several countries of Asia view promotion of drug use among their populace as an instrument of foreign colonialist oppression. The zero-tolerance policies (including the death penalty for possession of quite small amounts of prohibited drugs) in those countries flow directly from a historical experience in which a drugged population became easier rather than harder to oppress. On historical grounds, and on observation of the Grass Roots Party (a political party in my state supporting legalization of marijuana), I'm not at all sure that easier access to drugs makes a populace happier or more free.
There's another reason they're prohibited as well - users tend to think a lot about interpersonal relations, society, power structures, etc.
Sorry to hear about your panic attacks, I've gone through the same thing as well, but likely a decade after I last took drugs of any kind. They're not fun. I sometimes wonder if maybe I had smoked a bit during my stressful times that I would have been able to put things in better perspective without having to resort to real mind altering drugs from the pharmacist. Who knows...
Yes, drugs are prohibited because the government is afraid that it will be brought down by junkies thinking too much about power structures.
To an extent this is trivially true, and it certainly inspires a lot of not-too-insightful discussion about how we're all stars, man, but it can also point out the important but non-obvious fact that your neighbor is a person just like you are, having exactly the same experience of consciousness that you are, and so is the President, and so is that bum on the street, and so is that person in the country across the river that you're supposed to hate. She's just like you, and you can't hate yourself. So it shouldn't be surprising (for this reason among others) that people who smoke a lot of weed find the idea of war to be a waste of time when, really, we could all just be relaxing with some good friends, music and food.
Is it really that hard to imagine that this idea, whether brought on by drugs, education, or meditation, is threatening to the few in power who use these artificial divisions to control the many?
Your ignorance of history is affecting your understanding of these circumstances.
There is a reason why drugs are prohibited in many countries. People don't use them "correctly" and can become messed up pretty heavily.
I took shrooms when I was 18. After an initial phase of a lot of hardly controllable laughter, I experienced the strongest fear that I ever had in my life. Basically, the fear to remain stuck on this trip - nothing unusual by the way, as I figured out later by reading reports from other people. The main fear for me was to be stuck in this situation where your brain isn't filtering anything anymore. I was literally sitting around UNABLE to do anything. I mean, somehow I knew how to do a more complicated thing (like building another joint), but somehow I was incapable of performing the necessary steps. It was frightening, especially since there was no supervisor who could lead me out of this spiral of fear. The fear lasted only for 2 hours or so, then the trip was over as I fell asleep.
But I had panic attacks for another 6 months. Also a very typical time frame for many people. No fun. Stressful places, loud dogs, everything noise sort of made me feel anxious. On the other hand, it was a time where I thought about myself A LOT. I mean, really a lot. After 6 months, I somehow emerged with new self-confidence which grew a lot over time way beyond the self-confidence I had before (which could also be just a side-effect of getting older, I don't know).
So, now I wouldn't like to miss that experience. I don't know how it changed me, but I certainly do recommend that people should never try hallucinogenic drugs without supervision - people who can help you mentally to escape states of fear.