I eat obsessively! help me!!!?

im fifteen and have been through alot in my life ! when i say alot i mean alot! ive always had a big appetite and have a quite large frame, and ive comfort eaten before but recently (in the past few months or so) ive been eating excessively ! im not fat anywhere else at all except my stomach. i look very pregnant due to my mive stomach and it gets me very depressed and at times suicidal, all my dads side of the family gain wait purely on their stomachs and my mums side are are all overweight ! i used to live in a bikini in the summer but this year im living in dark baggy tops. in a typical "bingeing" i can get through two large tubs of ice cream , 15 bags of crisps , a LOT of chocolate , entire packets of biscuits , an whole mango/melon etc and pretty much anything else i can find! and what makes all this 10000000x worse is the fact im diabetic ! although i do manage to control my blood sugars. i do worry at times!! my best friend attempts to help me loose Weight and is very supportive even though we never succeed , and i do get especially embarred because she is extremely thin with no stomach at all! ive asked my mum to help me but i dont think its going to happen due to complicated reasons . has anyone got any big incentives or ideas for motivation for me to think of? or any good weightloss ideas? ANYTHING? thanks!