Hi.
I think you don't need to lose any weight, really, you must be fine like that.
Eating poor meals (specially a poor breakfast) and exercising a lot will not make you slimmer, because you will not be taking good care of your body.
You, as everyone else, need to give fuel to your body so it can work properly.. I can even have the opposite effect: as you don't give enought food to your organism, it will keep every little thing you eat - you can even gain weight that way. I know because it happened to me...
Your friends are trying to help you, listen to them...
If you really want to lose weight, talk to a nutritionist - check at medical schools, for exemple. At universities, doctors aren't usually so expensive.
I'll be here if you need to talk or anything else.