Perfect

my parents think I'm their perfect child, because my brother is depressed and used to self harm. He's on medication now, but still. I don't do self harm, besides picking, and I don't know about depression. Anyway, they think because I don't (As far as they know) self harm and isnt depressed. I feel so... Chained. Forced to keep that status as their perfect child. How do I escape that? Are any of you like this?