Not many people I worked with complain about this symptom, but it is one of the common symptoms of anxiety and panic attacks. I myself suffered a lot from this symptom.

I recall the times when I was preparing to go to an event, to give a speech, to host a gathering, I would get anxious, and my mouth would dry up to the point I can’t even speak or swallow. I would drink water to alleviate the dryness, but it would return shortly. I would be full just by constantly sipping on water.
Dry mouth that comes with anxiety can be very intense. I remember some occasions when the dryness got so bad, it spreads down to my throat. I felt like I was choking and ended up with a panic attack. Or the dryness from my mouth would spread to my eyes and make me sleepy. It was terrible.
I was told that once our body is under stress or is in a panic mode, fluid is directed to the major organs to help us fight danger. That’s why our mouth feel dry when under stress.
I don’t suffer with dry mouth symptom from anxiety anymore. It does come once a while like it does to everyone. I just applied A.C.E.R. Method and let it be. I do find some products that I personally recommend when your anxiety dry mouth become too debilitating.