Don't beat yourself up like this. Look at it this way, you completed 3 days. Also you are totally aware of what is happening and the fact you own up your own mistakes.
Next time, perhaps you do not set a goal. Do 1 day, then think you will be able to do the next and next. Sometimes keeping track of how many days you have been fasting becomes a road block.
Also still re-feed your body properly now, it is not too late, I am sure the next fast will be better if you feed your body correctly.
I think you did well, I gave up once in 1.5 days.....so you are way ahead that way.