Your always going to feel under-prepared going into a race. Pre-race confidence comes from within not from training. Confidence is a tricky one. We as athletes tend to think that our training defines us. It doesn't. Our head defines us. For those of you who have missed key workouts recently, don't sweat it. The money is in the bank. Take this opportunity to throw caution to the wind.
Lost workouts are not worth the effort it takes to worry about them. Don't worry about them, they are gone. Focus on the training that has been done, and smile.
Goals for your race don't have to be as specific as you think. What about the goal of going out and giving it all you have to give that day. Remember when we get to the starting line without any mental hic-ups we can race in a way that will indicate where we truly are physically. Just get there ready to have a good day and don't over think where you are at. Give yourself the chance to surprise yourself.
Every single person I know that is training right now has put in the work to have a stellar performance. Every single one. I don't personally know a single athlete that is slacking on the physical front this season. I do know a few however that need to sharpen up their heads. Do your body a favor and work on a clean and clear head.
I have now officially given you permission to let go of any apprehensions, and to seize the opportunity to race with a clear head, and to become accepting of your current fitness.