That's really great you were asked to do this.

Can you ease your stress by making the "talk" as informal as possible? For example, don't separate yourself from the group by standing up at the front of the room. See if you can all sit around a table for a chat. Don't stand up. Just sit there and be one of them, tell them your experience, and answer their questions. Invite them to share their experiences too.

Let us know how it goes!