Ya know, a little paranoia is a healthy thing … it keeps you alert and ready to respond to real dangers. Never lose it entirely.
However, try not to go overboard, either. If you do that, you lose out on reality because – while it is true that many things can kill you – most of them don't even know you are alive and if they do, they don't mind.
Kick back. Have a beer – or three – and just know that you will live out your years somehow and then they will end. Try to enjoy the ride and get some real work done. Leave the world a little better than you found it and don't waste your time wrapped up in fear.
I died once (drowning) and it's actually pretty cool – it's not worth fearing. It's the thought of dying that is scary … actually doing it is kind of fun. ;-)