You'll be ok. I definitely don't think you have peaked too early in your career, that would only happen if you did crazy workouts all the time and ran like 60 miles a week as a 13 year old. I think it's a product of getting sick and just not being in the best shape yet. Don't get too worried about it, some people hit a plateaus periodically and it takes a couple months or even a season it get another drop in time. Its all about staying consistent with your training and training smart and you will be just fine.
As far as training schedules goes, I would recommend doing this:
Saturday: run an easy 15-20 minutes, as slow as you need to. This is a recovery run so the point is just to get your blood circulating to promote recovery after 2 days of racing. Go slow absolutely no faster than 8:30 pace (5:20 per kilometer), slower than that is probably ideal.
Sunday: run easy (same pace as Saturday. From now on, when I say easy pace, this is the pace I am referring too) for 20-25 minutes. Same idea as yesterday
Monday: 3 miles easy. Add in some strides after the run. (In case you after done these before, you start out at an extremely slow jog, and slowly pick it up for about 50 meters. At 50 meters, you should be at full speed, then keep that speed for 20-25 meters and then slowly decelerate. Repeat for a total of 4 times.
Tuesday: I mile easy then do whatever workout your coach has you doing. Finding with 800m-1 mile easy depending on how you feel.
Wednesday: 3 miles easy
Can't remember off the top of my head what day your race is next week so Thursday and even Tuesday could change depending on how big of a race this is and what day it is. Feel free to email me if you feel that would be easier and more time efficient. Also, I know you probably use kilometres when training, so if you would like me to convert the miles to kilometres for you I can do that.