Although inside center and fly half are very similar positions, there is actually a huge amount of responsibility and leadership required from the fly half. It is YOUR responsibility to make decisions under pressure, lead the back line and make sure everyone knows what move is being done etc. I think you need to have a lot of confidence in yourself. Some of the best fly halfs in the world (look at Dan Carter) keep incredibly cool under extreme pressure, which is why I think they do so well.
You really need to communicate to your team as a fly, your backs depend on you to know what to do and where to go. if you can't already, learn to kick, it may help in a lot of game situations. hope this helps :)
