That sucks dude, keep at it, not many people do very well at all when they start to race (expecially crits becuase its easy to understimate the intensity of them) so don't be disheartened. If you want to race, train hard, eat well, and don't forget to warm up WELL. Sounds like you are keen, so you will be just fine. Good luck - make sure you keep us posted on your progress!!