If you have not yet seen the movie the king's speech I recommend it. There are many excercises to try that can help. If you are finding yourself getting nervous don't rush things and take an extra breath before annunciating. I found going a toastmasters club was very helpful in making me comfortable to speak in front of people. There's also a book called the power of the introvert that has a section about social anxiety and tips to cope. Sometimes if I get nervous in a speech session I'll fixate on an object in the room and use that as reference point to discuss topics or bullet points for example and when i am finalizing my take I'll make eye contact with audience very briefly to different members. Best of luck