Longest I've done was a 7 water fast just to see if I could
Around day 3, my eyes were twitching and I felt like death (basically sugar withdrawals)
Day 4-6, I felt like the world slowed down but I felt "clear"
The last day is when I actually felt serious hunger and knew for a fact that it was hunger
That was maybe 4 years ago and since then, I've mainly done IF + OMAD (One meal a day) because it's the most convenient and natural way for me
I'd never attempt a dry fast tho