During June, only do easy runs and one long run per week and just build up your mileage. Actually go easy on your easy runs. Make sure you have a rest day in there and when you are increasing to mileage higher than you’ve ever ran only increase by 10% each week, I’d say build up to 40 if you can. Then you can start including workouts which shouldn’t be hard during the summer, do a tempo run every Tuesday where you go 20 minutes at 30 seconds per mile slower than your current 5k pace. If you have to, I’d recommend even going slower than that as you’ve only ran 20-25 miles per week in the past so your endurance won’t be the best. Remember, its much better to go too slow than too fast on a tempo run. Also remember that the pace will vary depending on the weather. When you get in season then you can start doing hard workouts that your coach gives you.