This only happens to me if I eat a sugary meal when I finish my fast. Usually I end my fast at home around 4/5pm after work if I am doing 20:4, but somedays I do 18:6 and will have a little snack at work before I leave. Someone brought in a lot of treats so I thought eh why not and had a few pieces of chocolate and some fruit (I did stay clear of the cookies and pastries)…oof was I tired driving home. I didn’t want to cook when I got home, just take a nap.
I get tired too. My glucose while still in a 22 hour fast was 75. This constant cycling is kind of hard on your body I think. Got really dehydrated after alternating 24 hour fasts for a week too. Think it’s important to ease into things and make sure ur not putting ur body into too much stress from the shock of not having as much food as usual.