It is a tough diet to follow even when fully supported. Doing it privately is even tougher. I only told a few people when I did TFR. I had a shake in the morning, drank loads of water and coffee through the day, had a second when I got home and the last one at about nine o'clock. So it can be done.
Think carefully about your reasons for following TFR and take it a day at a time.
Rely on water as your best friend. Keep a bottle with you at all times!!