Who is in the right, and who is in the wrong? Relationship problems.?

Well, I'll try to describe this as best as I can. Basically, my girlfriend invited me to a rock concert, and I told her yes. I first needed to find out if I could go however, and she started to get a little irritated and slightly saddened because she might not get to go to one of her friends house for about 40 minutes before the concert. Anyways, this started escalating to her being very sad because she could no longer go to her friends house for as long as she had wanted it to, and she said she didn't want me to come. She also said she didn't know why she even invited me. She thought I would cause trouble (which I would not) and she no longer could go to her friends house for as long as she wanted to. So then I just decided I wasn't going to go because of how "badly" it was inconveniencing her. Then she said she just didn't want to do either anymore because she said I would be sitting at home feeling bad, and she would be feeling guilty. I tried to get her to go anyways because I thought she would have fun, but she wouldn't listen and was sounding more irritated by the minute. She also tried to turn this around on me and said I shouldn't have said I wanted to go. Then she said she needed to call her friend to let her know that she wasn't going, and I told her to call me back at her convenience (didn't want to make her any more mad; she has had emotional out breaks like this was turning out to be before, and if I had done that it would have turned out worse). She then said in an irritated and upset voice that she wouldn't, and hung up. Advice please?