First of all, Congratulations! One, because you have completed 7 or 8 days of fast, second, because you are eighteen and doing this to help yourself. How awesome is that!!!
You can expect an average of 1lb per day, sometimes more sometimes less. One fast may not do it. Chiron has a good advice for you. After the fast of 30 days you want to start eating only plant based foods and nothing processed. This way you will continue losing weight and rejuvenating.
You put on weight slowly, so expect to lose it slowly, it cannot be done overnight.
I have never really fasted to lose weight, but just cleaning and healing. I have never experienced true hunger, so cannot tell you about that either. The longest I fasted was 22 days and lost about 30lbs.
You may want to walk everyday for 20 minutes without too much exertion.