Well that answers a couple questions but not
When did you start running 35 mpw?
How often did you run?
How fast?
How often/how many races did you run?
What did your week before the 18:20 look like?
Right now it seems like you ran 18:50 last year. Then didn't run a step over the winter. You managed a 5:18 in the spring but didn't train over the summer. You started running 35 mpw and workouts way too hard in mid-August.
You need to run 13 out of every 14 days for the next year. Some of those 13 days might only be 3 miles with strides but not more than once a week. You don't want a sharp peak to 65 mpw, you want a slow increase from now until next August. 3 weeks during that time should be 20 miles the rest should be 30 slowly increasing to just over 60. Except for the 3 weeks where you only do 20 miles, the rest of the weeks should have at least the 2 Malmo workouts unless you have two meets in one week. I'm sure track will have a few weeks with 3 hard days but try to not ever do 4.