i had a very similar experience, and after reading a bunch of stuff on erowid i decided it was PCP also.

i was at camp, and this was before i tripped for fun, so i had only smoked before. so i just smoked a quick bowl, and i was sitting in the lawn chair looking at the clouds when all of a sudden i saw the clouds were morphing into these cartooney shapes. i just sat there staring at them until one of the other girls noticed me and was like "OMG your face is as white as a ghost!" and i was like "just leave me alone" and they were all like "omg omg we're drunk, you're dying." and they thought the best idea would be to try to get me to walk around, and all i wanted to do was lay down on the grass. so i don't remember a lot after that, but apparently i started punching people and spent the rest of the night laying outside on the ground. in short, it was not fun and i would never do PCP voluntarily. from the sound of it, i guess it finds itself into weed on occasion.

good luck next time, hopefully it doesn't happen again