losing weight

hi im new here and i have a couple of questions i have that i need answered. i have done four  3 day water fast (i have water fast for 3 days in the months of may june july). i have quit all of the because i couldnt fight the hunger and living in a house were people is always cooking is very hard. but im ready to get this weight of i been gaining weight ever since i was born. lol im 268 and i plan on doing a 30day water fast. with some workouts about how much do you think a big person like me could lose. i knoe on advage people lose 1-2 pounds will i lose more because im bigger? im not worried about gain it back because after this diet i plan on eating much better than what i am now. i just have a huge belly that i want gone. by the way im a student in high school so it EXTRA hard on me.