Never really hungry?

I don't get hungry much and I can't eat much. I wake up on a school morning, even if I'm not hungry I make myself eat 1 or 2 slices of toast, then I don't really get hungry at all and don't eat during the day at school, then after school I'll get hot chips and make 2 min noodles when I get home at about 4 or 4:30 and then I won't be hungry again at all? 
If I eat straight from school then I can't eat dinner because I'm not hungry and don't feel well to eat it. I hardly get hungry lately but I have a little habit of when I'm bored I'll go and snack on something small but I hardly do that anymore, makes me feel kinda sick? 
And I'm always thirsty, I drink so much and I'll finish a glass of drink and want more
Thoughts?