I generally feel very confident with people but my tongue sticks to the top of my mouth when presenting "formally"

comment by John Butler.

The speakers dry mouth is due to the adrenaline surge when giving a presentation. Ever wondered why there is a glass and jug of water provided for speakers at large events? It is because they often have a dry mouth too. So have a glass of water nearby to sip from occasionally; not too often as to distract the audience but enough to help you.

The other important factor that alleviates dry mouth is preparation and practice beforehand so that you have a greater confidence in your speech.

Finally, remember that most audiences are on your side, they want you to succeed with your talk.

An unexpected benefit of the adrenaline surge for me is the positive buzz at the end on having successfully completed a talk!