I used to be a jealous girlfriend, I never tried to control him though, just felt bad about certain things...the reason why I felt paranoid and was jealous was because I didn't have a very high opinion of myself at all and him flirting with other girls made me feel more unwanted and more unattractive, since then I have actually managed to grow up and start to appreciate myself more..my point is that maybe she's got a low self-esteem, maybe by just showing her that you do appreciate her and prefer her to other girls will help to stop the jealousy. Also, like others have said, don't give in to her demands, by her controlling you like that it shows a serious lack of respect if she doesn't expect you to have a private life away from her.