If you or your employer can afford the 12-week (one 3-hr class per week) Dale Carnegie course, it can likely solve your problem. There are courses in most major cities globally. Proven over decades.

You could also see a speech therapist to assess specific areas that need improvement.

The most valuable advice I received on reducing anxiety was to practice speaking on a topic in which you are the expert. There is one guaranteed topic in which you are the expert: your own life. Tell a 90-second story about a life experience that is meaningful to you. Audiences care about stories, not speaking. If you care about your material, they will care about what you say.

http://www.forbes.com/sites/work-in-progress/2012/04/19/publ...