Stop obsessing over unimportant details like weather and HR. You are telling us your mile splits to a tenth of a second, really?
Ditch the HR monitor. For some people it works, but you are clearly obsessing over it. No more heart rate for you, doesn't matter if it is resting or standing or max or during your run or whatever.
Turn off the auto splits on your GPS watch. Change the settings of your watch so it only displays distance. No pace information.
Follow a higher mileage 5K program by Jack Daniels or Pete Pfitzinger (you can download their books for free at libgen.io).