my girlfriend is against the idea of letting our social circle know that we're together.

she's assured me that it's just her personality and that it's not that she's ashamed or anything...but i still feel uneasy about it.

am i just paranoid/delusional/not being understanding?

Relationships never stay hidden for long. One of you might make an unintentional mistake, but more likely it'll be sensed (especially by females). Seriously, it might work for a few months at max. Just play along if it pleases her; the thrill of hiding it is quite fun too in the beginning.

Make sure she knows it won't last forever, though.

OP here.

yeah we've already told a mutual friend due to circumstances like you said. and people in school have already been talking about us since we're always together (although we're not affectionate in school)

but she's still averse to letting the general populace know.

Sounds like she is embarrassed by you

she is probably just averse to the general populace to begin with and having another aspect of herself to be judged causes those feelings to be even stronger. Or maybe in terms easier to understand she is not used to being in relationships and is afraid of how people will think of her for dating someone. Maybe she is projecting how she views relationships on herself like maybe when she goes out to public places and sees couples together she gets angry or jealous so she doesn't want people to feel those same feelings towards you and her. The human mind is simple like that sometimes