Alex, if I've got this right you're 15 years old, and run about 30 miles per week? I don't know when you started on your life plan for running, but I would say that because of your age you will develop differently to adults in a running club. Running lots is an answer, but only part of the answer. You need to train differently to adults as your natural VO2max and HR will be higher. You need to do some harder training to improve the VO2max, and it may be better to concentrate on long sprint or middle distance efforts, backed up by lots of easier running.
I note from other posts that you've made that you believe that you have to make each 5 mile run you do hit a certain, faster pace. This isn't the optimum way to train for you, or anyone. Not at least whilst your pace is where it is now. I think you should try an athletics club, doing middle distance training, as part of a longer term plan to get a great marathon time. Many, certainly not all, elite marathoners are middle distancers who've moved to longer races, or great track racers in their own right. You have age on your side giving you the opportunity to try this out, improving your strength, speed, and pace tolerance, before concentrating solely on longer distances on the road.
Good luck! I hope you maintain this level of motivation!