I think the closest I've felt to that was when I was working for more than 24 hours with very little sleep, and still have a lot of issues to resolve. If you are not sleep deprived, I think you might be feeling overwhelmed. You could be juggling a lot of things at the same time, and your mind and body are having difficulty managing all of them. Rest and relaxation is also important. I think slowing down from time to time, maybe just do some breathing or maybe writing your thoughts like now, can be helpful.