Yea i'm gonna agree with most everyone here and say thats pretty shitty of her, if its not a serious relationship that you want to put the effort in to i would recommend moving on and finding someone who is understanding and accepting of your quirks, we all have them. Its not something you can easily get rid of in my experience, i have stuttered for my whole life and have only been able to make it happen less but not completely get rid of it. Mine is also tied to my anxiety level. Good luck,