My running has been bad this year. Tips? Comments?

[teyo]

I'm a student and an athlete. I've been running pretty well for the past two years, getting PRs (personal records) at many of the races I competed in and not having too many injuries each season. However, this year has been stressful for me, what with a heavier load of school work, less sleep, and trying to focus on my academics to get into a good college. I am wondering, is there anything I can do to improve my running and racing? Beginning this track season, I started running with the fastest group on my team but I have not improved in times and, in many cases, have actually slowed down for my mile time.

Any tips on what I can do to become a better runner and have a better season? Thanks in advance.