Dead legs? Sinking like a rock? Lethargic in general? Yup- sounds like you're ready to me!
You're going to do GREAT!!!! You'll get out there and have the best race that you can have on that given day. It's what it all comes down to anyway: how you feel on that one day. No matter how hard you trained (or couldn't train because you started your own business and were working like a mad woman to get it going), you will do great for RM on that day. We're all getting excited for you... (and knapplaura, and who else?)