Like said before, being relaxed plays a big role in whether or not you get paranoid or have a bad experience while smoking. You may not be able to force yourself to be relaxed and calm, but thats fine. Just smoke whenever the time is right... Dont sit around and wait until you feel good but perhaps on a nice day where youre in a good mood and don't have a lot on your mind to be stressed about. Try to stay thinking about positive things when you spark up and take time between hits. Hopefully you stay relaxed enough. If not, listen to some of your favorite music or watch your favorite tv show.

I can't say for certain if this will solve your problems, but it should make for a better smoking experience.