Assuming you're telling the truth, and what you had wasn't laced, I'd read the following:

http://en.wikipedia.org/wiki/Depersonalization

Cannabis can cause chronic depersonalization, I don't know if that's what you had but it sounded somewhat similar. If this is occuring, as it may be seeing how you're taking medication for something or other, I'd talk to a clinical psychologist about it.

Now, if it only happens when smoking, stop smoking. If not, then it can definitely be caused by other things.