The only thing that I get paranoid about when I'm smoking up, is if that rustle in the bushes was a skunk or not. My backyard goes onto some train tracks (not as bad as it sounds, really) and me and my friends hop my fence, and walk down the tracks to a little shack/shelter thing we constructed in the woods. There are a shit load of skunks around there.

I've never had a paranoia problem, even when high. So I can't help you there, but smoking with more people could help, feel safer in a group maybe.