Always believe in what you know and do. I know, it is easier said than done. Espacially when doing some performance on stage where you are in the spotlights for many people. I know the feeling very well, nervousness before, perhaps even during such speech. But realise, most to all people in the room will feel the same if they had to perform like you did. Most in the room will never say 'yes', when they are requested to do such speech. Those who do, are already brave.

From my experience I know it'll become easier after doing this many many times. The thing is, whatever one talks about, if one knows the topic, one can handle any situation on stage. I mean, even when forgetting the speech itself, one can talk about the topic without preparation I mean. Maybe the speech will not be as structured and organised, but who cares. And I know, you care, as I care when I perform, but that is good, since not being satisfied with your own performance makes you better. But keep in mind, for most your performance is great even if you believe it is not. Since as I mentioned before, most people don't even dare to stand up in the room to ask a question. Let alone they would take the stage.