Is this normal sibling behavior or is mine fucking evil

I (18) and my little sister (17) do not get along at all. I’m very emotionally sensitive and insecure about myself whereas she isn’t. She loves to use that against me and call me “big, biggie, big back” whenever she’s mad or annoyed. My older sisters (20s) always call her out for it because it’s straight up MEAN shit bro

It’ll literally be for the dumbest crap too. We share a room, so obviously I always tell her to clean up after herself because she’s so messy and it’s disgusting. She gets mad that I tell her to pick up after herself and tells me I’m just nagging

I literally went to do laundry for us (I ALWAYS do our laundry) and she got so fucking mad when I told her I’m splitting it into two loads?? She started calling me names under her breath as I walked out of the room, and when I turned around to ask what she said she just laughed

Thats not even the worst of it. She constantly makes me feel like I’m a waste of space