forget the music. you need to concentrate ON yourself, not away from yourself.
first off: get a routine. do you know foods that you can eat right before you run that won't make you sick while you run fast? if you don't, find some. eat those before your race, about 2 hours before and then a smaller portion an hour before. that will keep your energy up.
second: pace yourself. start off slow for the first mile (a full third of the race) and then let loose. sick to your stomach, jelly muscles, and walking are all signs that you're going out too fast.
third: control your breathing. breathe deep, measured, and with your diaphragm. breathing is fully half of the battle.
fourth (this kinda relates to 3): warm up. don't go into a race cold. warm up with a 5K by running the course, starting about 2 minutes below your target pace for the first half, running the next mile at a minute below, then using the final half mile to gradually ramp up to your race pace. this gives your muscles a chance to warm up and your lungs a chance to expand. and even with the warmup, your first mile of the race should be slower than your overall average.
finally: since you do well in training, treat your races EXACTLY like a workout. then once you start doing well in races, figure out what to do differently in races.
remember, there's no reason to be nervous. it's just another run. you're most likely not going to win overall, so there's no pressure there. you don't rely on winning to put food on the table. you paid for the race; get your money's worth.
and if you have a running partner, how are you always way ahead of her? maybe your first goal should be beating her in a race . . . you may beat her in workouts but if you can't put it together when it counts, who's the better runner?
