Given everything, my advice would be to swap several runs for longer cross training sessions and strength work, assuming you've got access to a gym, for a few months, then increase the running again. For example, for the rest of this year do something like this (vary it by week, make each 4th week much easier, take a day off if you want):
Mon - leg/core strength - squats, split squats, deadlift, plank, situps, etc. Heavy weights, low reps
Tue - non-running aerobic - bike, elliptical etc. 60+ mins
Wed - easy run - 6 miles at 10:15/mile, plus strides
Thu - harder run - 4 miles at 9:20/mile (warmup 1 mile at 10:15+). Make an effort to do this.
Fri - upper/core/leg strength - similar to Mon plus upper body exercises. Heavy, low reps
Sat - non-running aerobic - bike, elliptical etc. 60+ mins
Sun - 8 miles at 10:15/mile, speed up over the last 2 miles if you feel like it
Lose weight but not with a faddy diet, just eat less and better. Everything in moderation but reduce junk food and cut out soda completely; make water your main drink
Sleep 7-8+ hours
Do a short dynamic warmup before runs (lunge, swing, jump, buttkick). Static stretch after (calves, hamstrings, flexors, etc.)
See if you can get some fire going for this challenge. "Jog a lot" (20 miles) is too casual to do this - get some fire in the blood. Watch some famous races/documentaries on yt. Look up Jo Pavey.