My friend has that problem. He gets anxiety attacks and starts freaking out. He doesn't get high that often because of it. Myself, I've been smoking for about 5 years and he's been smoking for about 2. Of course, he's only toked like 10-20 times those 2 years where-as I'm around 500-600 times at least so...experience counts I guess. I don't get paranoid anymore. I guess you just have to learn to be comfortable with the high and realise that it's something you yourself depend on. If you let your self-control go and start wigging out, then that's your business. I managed to get through my bad highs through force of will, but some people can't do that. Just smoke up, be in a place thats comfortable and safe to you, and you should feel alright.