Can u help me please?

there is this girl in my chior cl who always try to sing over me and is rude. like for instance i sing loud she tries to sing louder i sing a solo she and 2 other ppl talk all loud and be rude. and she tries to be like whoever she hangs out with she is never herself. she is always rude to me and i dont know wat to do. now the guy in chior(his name is sammy) who ive been crushing on for a long time stopped taking intrest in me and now is starting to like her. what do i do?