Hey airgirl,
Don't worry yourself, we've all felt that way. If your instructor says you are ready, you are, trust in him/her. I did my second first solo (helicopter) 30 years after my first. I was really nervous. I did ok, even landed back on the dolly (really un-nerving!).
Many times over the years, I have thought to myself: "Oh, I'm fully into it now", just as I got airborne. and a few times, I was fully into it! (but those are stories for another time...)
Your instructor will send you in ideal conditions, and in an aircraft with which you should have great confidence, you'll do fine...
Tell us about it when you've got it done....