I went through the same problem about 4+ years ago when I started back up. I had officiated for about 2 years with about a 2 year break in between. When I started I thought I was ready to go and just jump into it again and be ready to do bigger games that first year.

With the help of some officials in my association I was in I got better mechanics and experience and now feel that I am a pretty good official, but always learning and trying to work on something.

In your case keep working at it. Work as many games as you can and attempt to go to the mechanics clinics if possible. I have found that starting up if you have good mechanics it will help you move up and make other officials think more of you. You may know the rules and be able to make the right calls but the easiest thing to spot when being observed are the mechanics and positioning that you use. If those aren't solid people observing you aren't going to think much of your officiating or at least lean toward thinking that you aren't that good.

Hope that helps a little.