When you pause, breath in suddenly and focus on your breathing; try to forget what you are saying and the situation (not like really forget... but rather just to not think about it); People who are listening to you can wait, what you are having to speak can wait, bc if you pause and relax you will eventually be able to speak what you want. Now this can be difficult when you are angry, sad, excited, or nervous, but try to practice and calm down.