If you look ahead, the program now cycles between interval runs and straight runs, so i would personally move on to the 5-8-5 run on week 6 day 1. If you're not able to do the next full run on week 6 day 3, then i would consider redoing thst week until you're able to run straight through. Also consider your route. On long run days or days i'm not feeling my best, I choose routes that start uphill and end downhill. It's a bit of a crutch but it helps me to push through on tough days.