Pacing is a well known technique used to manage chronic pain in conditions such as endometriosis, and also chronic fatigue.
Getting used to the idea of doing slightly less than we want to can be very difficult; so many of us make the best of “good” days by doing EVERYTHING we couldn’t do after a few bad days. Unfortunately this can perpetuate the pain and tiredness, and “pacing” is a method which helps conserve energy and pain by taking an active approach in the management of it. The idea is to break the cycle of pain, anxiety, tension, stress, more pain, and so on.
This article by Moodjuice is extremely useful, and can print out in A4 format for reference.