If you head up to the exit passage you can transform back to human to heal, etc, and then go back for the nests and other opponents there if you wish. I think you just need to defeat Zagan, though, if you don't mind skipping a bit of experience.
On the Xbox, in dragon form a burst of speed is triggered by the left shoulder button. On the PC this is done by right clicking or hitting the 'E' key.
Well Cave - How to defeat Zagan?
