Weight help?

I don't get it. I eat healthy, I exercise. I stay away from junk food. I eat my fruits and vegies, drink the recomended amount of water plus some. While my parents eat what ever they want, and do next to nothing and I still weight more than them. They losse weight, while I stay the same or gain. I've been to the doctors, they can't figure out why it is. And now a days I'm just not hungry. Like I'll eat because I know I should, but I'm not hungry. And than my mom repremands me when I say I'm not hungry. I just don't know what to do. I just want to loose this weight. Like honestly I couldn't stop crying in the mall today because I went up a dress size. Everything is getting bigger, even when I do eat the right amont I and excercies 1-2 hours a day. I don't get it. Can someone please help me. I can't do it by myself. I know my mom says that she's going to help me but she brings in foods that aren't good for us. Just because you two are diabetic doesn't mean you need cookies to keep your sugar in check. Fruits can do the same thing. As well as vegetables. I don't eat them because I know if I eat one I'll want more.