What drug causes imagining things and paranoia etc..?

NOT TALKING ABOUT WEED. I just got some weed and from this new guy recently and it was cheaper than everyone else which is weird but its really good and ive smoked it for past week. Just recently ive beenimaging **** thats not there, like it feels bugs are crawling on me sometimes, mainly on my legs. the really weird thing is even when im looking at my legs and i can see they arent moving and nothings crawling on them i still feel it idk. You think this weed could be laced with something? What would cause that? Paranoia may be caused a little bit by weed but not like this and ive smoked for the past 3 years, so please dont tell is from smoking marijuana. I was thinking like pcp or cocain, but then why would the guy charge so little for laced stuff cuz that should be more right? I really dont know anything about those drugs or anything else besides mj. Thanks