Good partners are hard to come by. You should be grateful to Allah that you have a fiance who loves you alot, is pious mashallah and prays for you. What guy wouldnt want that? You should count yourself lucky.
Sounds so sad and sick to me that your wedding is coming up and you have started having a relationship with someone who you have only known for a minute. You went to your girlfriends house and spent time with her alone. Did you not have any guilt in your heart that you have a loving fiance who might just be dreaming about her wedding and marriage to you yet you are having fun with another girl?
This is just a fling! Break it off with this girl instantly and if i were you, i would actually sit down and think if im really ready for marriage? You are confused right now!
Made me abit angry that you got hurt when you read your girlfriends text msgs and felt betrayed that she is communicating with another guy...yet how would you feel if your fiance found out that you are having a relationship with someone else!
Sorry - but this is just so so sad!