I would do three things:
1. Take your easy days slower (as many have mentioned) and focus on running well in your workouts and long runs
2. Supplement your running training rather than take days off until later in the season. I would cycle or ride a stationary bike so that you have zero impact.
3. Get stronger. You sound like me in high school. I was a skinny, weak b!tch. Doing some strength work helped me tremendously, especially in terms of maintaining my form. I recommend doing gravity exercises - pullups and dips. All you need is a playground with monkey bars and a bench to do those. Also, do jumping lunges to get your legs more powerful. Basically you stand in the same spot, lunge forward, and then jump to the other lunge position. Do 1 minute after your runs 4 days per week.
It is August. If you are going to be feeling fatigue from your training, now and September are the time to do it. You will be fresh and strong come October, which is the only part of the season that matters.
Good luck!