Speaking of which… Stress causes dryness in the mouth by raising hormones and neurotransmitters that cause a number of physical changes in the body.
Adrenaline for instance will cause the heartrate to increase, the body temperature to go up, and the mouth to turn dry. This is why you will often find yourself standing in front of an audience, sitting in an interview, or on a first date… struggling with a completely dry mouth and stumbling over your words!
It’s not particularly helpful, but there it is. That’s our body’s response! The best thing you can try to do then is to reduce the stress and let yourself become more calm. You can do that by using meditation, self talk (look into ‘CBT’), or by controlling your breathing. Either way, the worst thing you can do is to become stressed by the stress itself.