Either try a power nap or eat/drink whatever your body seems to miss today.

Sometimes, I reckon I'll just need to get some light sports or general activity outside going.

But most of the times? Nothing works and I kinda just accept that's it's a slow day. So do what must be done today, try to do something comfy/fun for the remainder and get at least something enjoyable out of this day.

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.

I hate that feeling! I've been trying to learn to take 20 minutes power naps, but not having much success. Sometimes eating something spicy or crunchy will wake me up a bit.

i just try to sleep, though that's often impossible if theres work to do

Sounds like depression or a mild hypomania episode. I would rule out medical issues for long term relief.

Go for a walk to the store and wander around before returning home.

Welcome to life buddy, just suck it up and keep going.