I finally mustered up the courage to leave for Whiterun. I laid awake all night, worried for the lives of everyone else, and I couldn’t just lay around and let a dragon kill an entire city because one person was too afraid to send word.
I left Riverwood and arrived at Dragonsreach around 4am. They seemed to have already been speaking about Helgen. The housecarl, Irileth, came at me with her sword drawn. When I spoke of the dragon at Helgen, she sheathed her weapon and told me to approach the throne.
Jarl Balgruuf was very gracious that I had come to him with the message. He’s sending a detachment of guards to Riverwood. He told me to eat and rest, and when I return, I can talk to Farengar, his court wizard, to help with the growing dragon menace.