I mean the days when you are tired, even if you eat well during the day, you are still hungry and irritated, you find it difficult to concentrate, and it is impossible to communicate with people for a long time, or even when you try to hold something in your hand, it seems to slip out.
Once you hit that situation you’ll have to simply wait for the body and mind to re boot. Nutrition helps but it won’t be a silver bullet in my view. What’s worrying is the note on communication, seems you’ve been running on fumes for a long time, to the point you can’t will yourself to push forward. Rest, hydrate, take vitamins and let the body resets itself.
Depending on the exhaustion it can be more than few days of rest, it can last a week or more, depending what’s your source of stress. If you can maybe take a day off from work, at least in the past I’ve had the luck of having a doctor that didn’t complicate if I simply said that I’m too exhausted to make a safe trip to work. Otherwise do the bare minimum and put other activities on hold, re connect with people after few days, even if you won’t be up to it. Socialization is important, even if you’ll feel more tired after the meet up, at least that’s how it usually went with me.