My mom hides candy from me because she thinks I am fat. Advice?

When I was 13/14 i hit puberty and gained some weight. Ever since then, my mom has been bugging me about it. Telling me to eat less candy and lose weight. I don't eat enormous amounts of sweets at all (I could eat less, of course, just like most people). And now I'm 19, so this has been going on for like 5 years. I have had low self esteem and body issues due to my weight and have been yoyo-ing a bit the last few years. Lately I've gained some weight again and now my mom is really picking on me about it. Always if I'm eating breakfast she "accidentally" walks into the kitchen to check on what I'm eating, and if I look like I might eat some more for breakfast, she says she can "tidy up after me", just so I won't eat more.

Last night, my brother bought lots of candy, and the first thing he did was to hide the bag of sweet/sour gummy things from me. So now my mother has dragged my brother into this and I know he's been ratting me out to her about eating candy. And today I really had a sort of breakdown. I asked my brother if I could have some chocolate, and he lied to me about it, but of course I found out, he's the worst liar in the world. I proceeded to search the house for the stuff he bought last night, and finally I found it LOCKED into his school supply cabinet by his desk. Along with the peanuts I'm not allowed to eat. I now feel really betrayed by my brother and I resent my mom and dad for bitching about my weight, and I've been crying all night and feel like a fat loser, whose family has to hide food from me.

I am 160cm (5'2) and weigh 62kg(137lbs), which means I am within the range of what is considered healthy. I don't think I'm fat, I have a little extra here and there, but I'm not overweight. Needless to say I'm not close to my family when it comes to talking, but any advice on how to just feel better. The usual "you're fine the way you are", is starting to bounce off me and I'm feeling really down.