I have been that tired. The MS MD said it was all part of the game, and warned me against pushing myself to the point of falling asleep at the drop of a hat. Make sure your MD knows about this level of exhaustion, and the details of your schedule. Are you sleeping at night? Do you snore? If you snore, you may have apnea (breaks in breathing) and that can cause you to not be resting, even if you think your asleep. it can lead to overwhelming exhaustion. Then there are the meds we take, and the need most of us have to get up and keep going. its hard to find your balance. Keep a journal. Write down how many hours you are awake, and what you did with your day. You may surprise yourself.