Find your own rhythm at work and don't do more tasks than you feel you can. In case you're too exhausted, delegate some tasks and give more time to your health and your overall wellbeing. There are so many things to check!
Start with food sensitivities, then have a thorough physical exam, and, to fix the result, find a person who will help you organize your personal fitness program. Be sure that your body will be thankful for what you're doing!