Water Fasting Encouragement and Advice

Hi,
I've been trying to Water Fast for the past month without much success- the longest that I managed was 3 days.
This forum has a lot of inspirational posts and I've joined looking for advice and encouragement. I really would like to succeed to at least day 5 which I know is the hardest. Ideally, I would like to Water Fast until I am back to the weight I was 3 years ago.
In the past 3 years, I have put on 20kg. With each kilo I'm becoming more worried about diabetes as I have a background of PCOS.
I have a breakfast scheduled with my boss the morning after tomorrow and I plan to fast until then. I then plan to do a proper Water Fast afterwards for 28 days, longer if I can manage it.
I work in a job that requires me to manage walking around a decent amount and to be switched on at all times, often the environment can become very stressful.
I would really appreciate
a) advice on maintaining energy and concentration on fasts
b) what everyone does about needing to eat out
c) if I was to eat out, any particular food that I should choose?
Thanks!