I'm a WHAT?! (Percy Jackson fanfiction)

This is my first fanfiction so please take that into account when reading this. This is somewhat my self insert fanfiction or how I would act if I found out I was a demigod.
Hi my name is Niamh and up until now I was convinced I was just as weirdly abnormal as the rest of the population but the world just had to prove me wrong. I mean my family was big enough with the six of us tryna find a place to fit in this world only to find out I am adopted and AMERICIAN! I mean I was happy being born and raised Irish. everything I thought I knew was wrong. my parents, not my parents, my siblings, not my siblings, my heritage, not my heritage. well you get the point but as it turns out I am not only American but not even fully human.