Not sure what you did but my first Water Fast in 3 years is still very clear in my mind. I thought I was mostly healthy and I did several 1 day fasts to prepare me to my 4-day, but the 4-day fast just blew me away. There was no way I'd have ANY chance of working during my first 4-day fast at all. I was dizzy at times, super tired at others, confused, my body was irritated (unable to sleep or do anything), my stomach and liver were repairing, it was ... ughhhh.
So it all depends on how much experience with Water Fasting you have and how healthy you are. Stress is usually not a good thing. Doing some 1-day Water Fasts or doing a 14-day orange juice fast may be a better option for now.