Surely this your late teen daughter, who has just left home for the first time? I just can't begin to understand how you could let yourself be treated like that, unless it was someone you had given birth to.
But of you were her mother you would be being told (and probly not in a nice tone by most of us), that you stopped trying to be your daughter's friend, and to be her mother instead, which means either letting her learn for herself the hard way, that being totally self absorbed, entitled and rude, will get her exactly no-where in life. Or you could be kind to her, and tell her that she will very quickly run out of friends, and friendly colleagues, and explaining to her exactly why.
Luckily for you OP, she isn't your own flesh and blood, so you can easily point out her terrible characteristics, and then block her. Unfortunately, you might need to find somewhere else to volunteer, otherwise you may never be completely free of her!
Good luck OP, you are obviously a lovely and kind person, but you mustn't let people walk all over you. Please believe in your own self worth. 💐