@rahve: let's put aside the judgment on looks, since it's absolutely subjective - i've fallen for people who have underpar looks, and you have too (fallen for people who don't look perfect, i mean), while we both have felt no attraction for people who look great (like, you're not attracted to me
). so you know that appreciation of appearances is a weird lottery.
on the other hand, i honestly believe she likes you: ok, you were depressed when you hung out with her, but i don't think that being depressed automatically makes someone not tolerable. you are not arrogant, aggressive, boisterous, stupid, macho, vulgar, which are the things a young, cultured woman might consider not tolerable.
i don't know her, but from what you tell me i can surmise that maybe she felt a bit sorry for your state - still, this doesn't mean that she can't find your company enjoyable. you are probably more articulate than most people she meets, you're always respectful and understated, and you also have some cultural interests in common with her. what's not to like? you think she believes you're a dickhead only because you were crushed on that specific night? maybe she's felt that way too in her life, and sure with all the gothic stuff she must have read for her job she can understand what you're going through.
maybe if you keep getting all depressed on her she might find you a bit single-minded, which could alternatively turn into "boring" or "creepy"; but you're still in time to have a perfectly normal friendship with her, of the go out, see movies, see shows, buy books together variety. thus spake the heir of slytherin.