Sounds like a nasty panic attack. I have had then off weed and shrooms and once when I was really stressed up over a girl, probably only 5 times in 9 years of doing drugs which aint that bad. Once you have been through them once or twice they get less scary. I just pace around and try to control my breathing only lasts 5 minutes for me though. Never had it as bad as you, I very much doubt it was laced unless it was by the person who rolled the joint.