Actually knowing where you are at puts you way ahead of the curve. Many developers don't even know they are not that good. If you love it and seem to have excelled already in a similar area you just need time. Even just knowing that good development is not just writing a quick perl script or copying and pasting the tutorial code or stack overflow answer is a good sign and would probably set you apart from most I know.
Which I think is fair from their perspective, I think they expected a developer by trade to have assumed the role, and in actuality it's someone who has done a tremendous number of jobs around development. I'd be a bit concerned as well.
The great thing is, I'm learning a ton of cool technologies, and already see the major progress on a lot of fronts.