You have only known this woman for three months! That really is not enough time to get to know someone. Usually, the first 6 months is the "honeymoon phase" where you feel like you're in love, elated, the oxytocin is raging, etc. it is not until that phase kind of wears off that we begin to learn who the other person really is. In the beginning, people tend to be on their best behavior and, because we are just getting to know them, who we think they are has more to do with our own projections and perceptions than with who they actually are. In other words, we see them the way we want to see them! It sounds like you are beginning to see this with your fiancé. The anger and paranoia have probably always been a part of her personality; she has just hid them from you or you have not noticed then because you were feeling all the happy love-y feelings and imagining her to be perfect. Please don't rush into marriage; talk to her and take the time to really get to know her. If I had married any of the women I dated at the 3 month mark-- geez! What a mistake! It takes at least a year or two to even scratch the surface of another human being!