How EXACTLY do i break up with my girlfriend?

she whines 24/7 im so tired of it. Her birthday comes and she says, "wawawa i don't want anything, if you give me anything i'll kill you, wawawa im a little baby"...then i get her a car and all she can do is whine about how much her life sucks. i got us our own private island for HER and yet shes still so unfaithful and she thinks the whole world evolves around her azz. I do everything for her and all she can do is be a whiny little betch, im so bored of her. My stomach hurts just thinking about right now and i want to puke in her face.