Hello Yunieloveyu!
I know exactly what you mean by hating to be unique. I could have written practically every sentence of your post (which bears some irony in it... ). Everything about me is different, too, from my innate personality to banal things like what music I like, what teachers I like. A girl from school, not a friend, but rather some of the very view people I talk to at school at all, once said I always hate the teachers everyone likes and like those nobody likes.
When I tell people I feel that absolutely nobody understands me, they usually don't understand me. LOL. It sounds arrogant. But it's actually about the pain of feeling totally un-understandable, my actual weak point is the feeling that I'm incomprehensible, that I'm crazy, and weird, and probably even warped. So like you I wish I was just basic like everyone else, thinking like everyone else, so that I could feel normal and be understood.
I think this pain of feeling not understood is also what upsets you about other people not understanding what your pictures are meant to show? From what you write, it seems like you have an abstract sense for aesthetics and a very personal style in your drawings. At least your art teacher should appreciate that!
What you say about your own little fantasy world sounds familiar to me too.... have you ever heart of the term "Maladaptive Daydreaming"? The name sounds judgemental, but if you look into it there are lots of forums for people who have it. There's also a social group for daydreamers on PC, maybe you want to check it out:
http://forums.psychcentral.com/groups/daydreamers.html
P. S. Welcome to PC