Yes I must agree with Martian and say that Snowy is one of the only women where the "don't argue with females" rule truly applies; what makes her so great though is that she'd never say it
Sounds like a basket full of unhappy for you. It's possible you're like me, have a savior complex; you love to date girls who are a little bit of trouble, though completely unintentionally, with the hope that you'll make them "better" and it'll be you doing it.
That is one of the many classic signs you are in an "unhealthy" relationship. Put aside her obvious need to grow the hell up ("No I'm Right! Nah, nah, nah, nah, NAAAH nah; I'm not listening!") and her very obvious eating disorder, it seems like you are completely aware this is going no where fast but refuse to jump ship because of the aforementioned "I really care about her and if I stay, maybe she'll change".
The sad truth is, she won't.
(BTW Mart; I never noticed your signature before. You are perhaps the only person I have ever met that can make a Journey song sound poetic. I don't know why but when I read it, it automatically went into "Sir Lawrence Olivea" mode... well done)