why aren't my paces dropping

Could be a variety of things that are wrong with you, and it is hard to say because I don't have enough background info on you to give a definitive answer. Are you injured a lot? What's your diet like? It could very well be a vitamin deficiency/anemic. Get a blood test and check off all the basics you wanted to get tested for (you can probably find that on another thread). Although the paces of your easy distance runs are sort of irrelevant (since easy pace is subjective and you were probably running too fast on your easy runs as a frosh: rookie mistake), the fact that your race times have no improved is what is concerning. Although this is unlikely, you may be struggling with something mentally as well.

Good luck!

I never thought it was something physically or mentally, only because I've never had an injury unlike many girls on my team, and I am a pretty consistent racer. Thanks for your input, though!

It can be kind of hard to get your training paces to drop when you're trying to get your training paces to drop. You need to allow it to happen rather than trying to force it to. I have a "rule" with people I've advised that they can measure their runs either by time or by distance but not by both except in rare and specific circumstances. Don't worry about your pace. Just get your miles in and get more of them in as time goes on.

You need to increase the stress load as you progress in high school. That can be total mileage, total volume of quality workouts, density of quality workouts, increase of speed in workouts, more "stuff" to do in workouts. If you don't progress your training you shouldn't expect to see many positive increases in your performance.

You also need to evaluate your health. Nutrition, sleep, etc.

HRE wrote:

It can be kind of hard to get your training paces to drop when you're trying to get your training paces to drop. You need to allow it to happen rather than trying to force it to. I have a "rule" with people I've advised that they can measure their runs either by time or by distance but not by both except in rare and specific circumstances. Don't worry about your pace. Just get your miles in and get more of them in as time goes on.

I came to write "you're running too fast." But it's basically what HRE said. Just run. Run easy. Don't worry about. Then one week or one month you'll be floating along and go, huh, I just nailed some pretty quick paces.

But chase it too hard, and you won't find it. It's funny, with running and so many things people talk about putting in the work and working hard. Those things are both true, but they don't tell you that often the hard thing about the trial of miles is they get boring because you have to slow down a bit.