Increasing mileage head says YES and body says NO

I think my body told me about a week ago that you can’t keep upping mileage and intensity week after week without reaching breaking point. Achy hips, heavy legs and no energy were the signs after 6 weeks of my marathon training, luckily a week of shorter runs and longer rests seem to have done the trick. Now the key is will I learn to step back before I reach this point next time or will it take the same message from my body to take a step back?