yesterday i was at sitting alone downstairs at my brothers house and had just smoked a dub.i started feeling almost sick for a few minutes but i couldn't figure out what the hell it was. we had grateful dead jamming some of their more dramtic tunes like blues from allah, unusual occurences from the desert and we CNN on mute on the tv. that was the worst experience i've ever had as a result of acid and i haven't tripped in weeks. that was my first experience with a flashback, or whatever you want to call it. it turned out to be about 15 minutes of hell for me. it felt like it was about an hour and i couldn't control my thoughts at all. all that shit about bush and about the war with iraq and everything... that shit was crazy. as much as i know and have done lsd, that was my first non-tripping occurance. what's the deal with all this?
i can also say that i have had times that i felt very odd and trippy when i had not taken any acid in a few weeks as well. it sounds like your experience was pretty bad though, everytime that i feel like i have had some sort of a flashback it isnt nearly as bad as you described, it is usually just some visual disturbances.