My girlfriend is a dictator

I’ve been dating my girlfriend Stefanie for two years. I like her very much, she is nice indeed. But sometimes it is so difficult to be with her. She is unpredictable person and sometimes I really do not know what to expect from her. Everything might be just perfect and suddenly she changes. And to tell the truth I do not know why. She becomes irritated and doesn’t want anything. I mean I’m not a perfect person and I try to do my best but it is really difficult to predict what she really wants and needs. And to tell the truth I have no idea if she likes me. Some of my friends are sure that she just uses me. Well, I’m confused. It seems to me that they are right sometimes. Especially when she makes my decisions no matter what I want and what I need. It is irritating indeed. So she even doesn’t ask me. My opinion means nothing. For the first time it was okay but I had enough. Stefanie controls absolutely everything in my life. She decides what we would do on weekends, what we would eat and even what I should wear. Moreover she calls me quite often whether I’m busy or not. She asks me where I’m, what I’m doing and what I’m going to do. She is jealous.