i ran 4:24 and 9:35 in high school training 40-45 miles a week with a lot of speedwork. walked on at major D1 program and believe it or not our Coach was supportive. 7 walk-ons showed up the first day of practice in XC and only 2 lasted through XC.
the best thing you can do is increase your mileage immediately irregardless of how fast you run. if you can handle the mileage increase to 75-85 right away and want it bad enough you will succeed.
i ran 3x at conference XC, 3x at conference outdoor and scored for our team in outdoor in the steeple.
the biggest problem is that the workouts are always designed around the top guys, so many of my best efforts came in workouts. and i stopped running after college and never raced again from being burned out.
good luck.