Please help!!?

Hi. I have to perform base training over summer to get ready for the tough workouts for Cross Country in the fall. I am the fastest sprinter in my school, and I don't want to lose that. If I focus on cross country many people at my school are going to say that they are faster than me and want to race me. I have had a large amount of people think they can beat me. Now that everyone is moving to high school, they are going to start training for speed. Many might even go to be one of the state's fastest runners. How can I focus on cross country and have incredible speed. I know that many elite runners such as Alan Webb have great 800 and 400 meter speed. He doesn't run the 400m, but I heard that he can run a 47 second 400m in his high school days. I was going to perform speed drills (such as 4x100) in the morning on the days that I have a distance workout, but I believe that will lead to overtraining and less results. I really want great speed and endurance to be gained over summer.