I have reverted to a cycle where I wake up, never feel refreshed, then somehow get myself going by lunch time (perhaps the caffeine and the effect of food, I usually feel slightly better right after eating and getting my blood sugar up). Then I can keep going for another couple of hours until fatigue inevitably kicks in at 2-3 PM. This crash is the worst and lasts until evening and then improvement builds up to where my nervous system starts to get overactive just when it's about time to go sleep, which means sleep is often ruined as well. The shifted circadian rhythm where you feel most tired during the day and least during night seems fairly common in ME/CFS. Ron Davis has compared it to African sleeping sickness, which shows a similar pattern.