Why Am i Constantly Bloated?

[Angie.]

I am only sixteen. I don't usually eat breakfast or drink that much although i should, i dont like water so usually have to result to drinking bought sugary sweetener drinks such as Oasis and flavoured water which has sweeteners in. I eat lunch, usually crisps and a sandwich then a sweet thing such as a cake or chocolately treat/biscuit but i can't just have one i usually keep going even when i'm not hungry. I eat loads and loads at night time when i get bored infront of the tv, which is really upsetting as i can't control it. my whole family eat alot of sugar too, which i see and copy. I get depressed because i'm eating too much sugar when i don't need to and get bloated which makes me eat more. Someone once asked if i was pregnant after eating just three small cuts of french bread! I looked pregnant. Then, usually when i wake up my stomach is flat again. But as soon as i eat or drink, i instantly bloat and feel fat and frumpy. I've also got my prom in about a month and am worried about looking fat and bloating! Please help :(