My friend and I got into an argument yesterday. But it started some time ago. I have a car, she doesn't but she likes to call whenever and expects me to give her a ride whenever and wherever she wants even if I am far away and it's around the corner where she needs to go. She also gets really mad when I don't do exactly as she says. I really liked her, but I started getting tired of that. And I admit that when I get angry I become loud. So yesterday we were talking on the phone ad she wanted me to bring somebody to her house in 5 minutes. I said that my apartment had a fire alarm and that I first had to take care of my computer in case the roof water came off. She got mad when I told her that it would probably take at least 20 minutes. And because she didn't want to believe me, I got frustrated and I started explaining to her with a higher tone. She hanged up on me. But she called later on because she needed me for something. Now this morning, she sends me a nasty email saying that I was a mean person and that I was egoistical. She also said other bad stuff. I was like WTF?!? Well, I replied to her email, and I told her that, just because we're friends, it doesn't mean that I have to do everything that she wants, and that I also have the right to say no sometimes. She would make me feel very guilty whenever I did not agree with her... Anyways, what should I do now? She has a history of mental disorder, and I was her best friend. She's leaving the country tomorrow for a month and a half. I am not sure what to do next. Any advice is very welcome.