How do I get over my fear of public speaking?

I'm glad to hear from you; what you are describing is a prevalent issue that many people face when they need to do a presentation or a public speech; as you disclosed, a person experiences body symptoms such as shaking, dry mouth, among others as well as a lot of negative thoughts such as self-doubting, worries and self-defeating statements about the ability to perform, predicting a catastrophic scenario.

Many things can be done to reduce the impact of intense anxiety. For example, you can implement the following tips:

• Be familiar with the topic and organize the material; the more you know and more organized you are fewer chances that you will make a mistake.
• Challenge your worries and pessimistic thoughts by writing them down and finding pieces of evidence that support those unreal predictions, then, you will notice unrealistic expectations, and you will replace them with realistic positive ones; for example, Instead of thinking, "my anxiety will make me suffocated in front of the audience."  You will replace with "it is okay to feel anxious, I know the material, I'm fully prepared for this." 
• Practicing breathing exercises and relaxation techniques will reduce your level of anxiety; you can use those tools before or during the presentation.
• Try to practice in front of people you trust, it will reduce your fears by exposing you to a similar scenario.
• Focus your attention on the material instead of the audience, don't get scared of a moment of silence. Maybe if your mind goes blank would be for seconds, and the audience won't even notice; for sure, you are more critical of yourself than the people attending your speech. 
• Join a Support Group with people with similar difficulties, and take a course or training on leadership that prepares students for public speaking.
• Accept the idea that nervousness and anxiety are normal in certain situations as a body warns up for good performance. Before the presentation Identify, your success and efforts. 

Getting over a fear of public speaking is something you can achieve, so you are on the right path. Welcome to BetterHelp. 

Sincerely Flora Pazos