I'm sorry to say this, but what you are up to seems to be rather crazy. You want to live on 80 cal. per day and continue that fast for a period of 40 days??? you need vitamins, minerals and energy, otherwise you might get seriously ill. Where do you think you will get them from? After a few days of this kind of fast your body will simply collapse, because you cannot live on a single fruit and water for more than a few days. And even worse, after a short while you will develop a ravenous appetite, which to resist will be very hard. So, often people who start such a fast, end up with more weight. Ever heard about the jojo-effect?
Have you ever tried to add more vegetables and fruits to your daily nutrition while leaving fats aside. Maybe you can find some time to do excercises. That is how I could lose some weight.