Not exactly the same thing here but as a kid, my first nordic race (it was called Silver Creek Challenge)...I had to cancel my participation after getting sick a day or two before. This was my "A" race as it was also my first. What I learned was the JOURNEY I took to get to that point was a blast, I improved months leading up to the race. I decided to use that fitness I gained as a launch pad to another race...adjust the goals & move on. It wasn't the end of the world, it was just a stopping point (like a rest area on a highway). Reflect on it, what you can & will do better & now, you have more prep time towards another goal. So your feet are wet from sobbing about a cancelled race. Use it as motivation rather than sobbing in booze about it.

Sure it sucks, but it doesn't have to & life goes on. I've prepared for longer Birkie Ski marathons & they were shortened due to bad snow. Oh well. Gives you more time to get faster yet...