I hope you know I was just kidding about the marathon comments. Was not trying to bring you down (and don't think I could). Just trying to lighten the mood.
As Odog said, DO have faith in your training. Before the marathon I did, the longest race I did was a 10k. It is difficult to explain to someone that the human body, let alone their body, CAN do 26.1 miles. But, with the right physical and mental training, it CAN. And it is one he!! of an accomplishment.