My fianc? Told me she wants to go on break

I have been with my fiance/ex fianc? For 10 months and just last week she told me she wants to "go on break." I am 35 and she is 22. She lives an hour & a half from me. Since we met we have spent almost every weekend together due to our work schedules. I drive to see her on Friday afternoon & come home Sunday night. I also drive to see her one day during the week. She lives with her parents and is close with them so I always go there. Anyway she is adopted and a few months ago found online her biological mom,dad and sis. So we planned to fly and see them last week. For a few weeks before our trip we've been bickering about minor stuff. She said it was her being stressed out and I added to that stress. She said there was something missing and it has nothing to do with me...she's says I've been "perfect". One night I overheard her tell someone that she "loves me....but "isnt sure if he's the right one- how do you ever know" and that I'm "always up her ." I confronted her about it and she said she doesn't know why she said it. I give her plenty of space. When were not together she either goes to a friends house or meets a friend at a bar and drinks. Just recently she said she would like more girls nights out on the weekends since she's only had a few in 10 months. I have no problem with that but she said she was scared to ask me. She says every time she goes out we get into an argument. Sometimes this is true but all I ever asked of her was to "every once in a while text me"...she feels she shouldn't feel obligated to do so. So the night before we left to see her family that she's never met I confronted her as to why she's been so cold and distant...she had no response and no reaction so I left her house to see how she would react. A 1/2 hour later she texted me saying how I'm the nicest guy she's ever met and I deserve better than her. I came back to her house and she said she wanted to take a break and that she won't wear the ring on our trip to see her family and she won't introduce me as her fianc? But she wanted me to come with her and meet her biological family. Half the time on our trip she was cold and distant and half the time she was ok. I told her I didn't want to lose her and she told me "dont worry..you wont" I also asked her when she's going to wear the ring again and she said "eventually". The 3 days Since we got back from our trip she's texted me but only once in a while and she called once. I don't call her and only respond to her texts but never text 1st. I don't want to lose her....she has everything I've wanted. I know she's serious about me because several times we looked at houses together and she has wanted to have a baby. She's very trustworthy and always texts me and tells me what she's doing even though I never asked her to.What should I do? Please help