I run, and I'm actually helping coach the XC team here this fall.
My fast tid-bit of advice: SPEEDWORK! Do get faster in a 5K you need to do speed work. This far in the season you should be dropping/levelling off in your milage, and your intensity should be spiking!
Make sure you listen to your body, too (i.e. rest when necessary, SLEEP, and eat well).
Good luck!
