I'm always depressed when I think about my life and my parents are stifling me..?

I feel like I'm worth nothing and that nobody wants me. My parents are stifling me and I can never do anything without having to tell someone what I'm gonna do. I also have Diabetes type 1. I'm always mad at the world because it always takes everything for ******* granted. I've told my mom about this and she always blames me for it. And her husband (not my real dad) is always trying to get me mad that I just wish I could find the perfect family. This isn't a little child hating their parents because they took their phone away here, I am always sad. My parents treat me like I'm 6 instead of 16. And my friends will ask me "Why are your parents so strict?" or "Why don't your parents let you do anything?" I feel like no one understands me. I also feel like I'm not worth anything and I look at myself and I think to myself about how ugly I look.. even though people are always telling me how cute I am or hot (not trying to be stuck up, just telling you what happens in my life). Please help me get through this. I basically hate my life.