Before a BJJ match I get Pre-match anxiety?

This weekend I am going to compete at a BJJ tournament, and im worried about the pre-match stress I always experience. I wrestled last year and hated going to any tournaments because of this. I don't know why it happens every time before a match, even though I tell myself its not that big of a deal. I have acid reflux which doesn't help the situation. I just need to figure out a way to calm myself down. Any suggestions would be very helpful.