The best thing you can do is practice the behaviors you want to have to yourself. It might sound silly, but the first step to obtaining or breaking a behavior is to simply do it.

If you want to stop being so paranoid, the first step is to stop acting paranoid, no matter how you feel. Acting the part will help break the cycle and you will begin to feel less paranoid, which will cause you to act less paranoid, etc. It's an attraction thing.

Think of it like this: If you smoke cigarettes, you're more likely to meet people who smoke cigarettes (you'll sit in the smoking section at a restaurant, you'll hang out by ashtrays, etc). If you stop smoking, you'll stop meeting smokers. Just as if you act paranoid, these behaviors will cause people around you to treat you as if you are paranoid which reinforces the internal belief that you are paranoid.

I can imagine that my advice might seem hard to put in to motion, but once you start, it becomes self-perpetuating.