Relationship Problems

My fiancé and I used to be the perfect pair, until she asked me to quit my job because I was miserable. She told me she'd take care of me while I finish up school because I was failing and everything would be just fine. So to save money she suggested that we move in with her mom... But her and her mom don't get along what so ever. We got stuck in this tiny little room with our two cats and it's been pretty stressful stuck in there together all day every day. So after moving in it went down hill. We started fighting non stop. We hardly have good days anymore. So we decided to take a break. It's been about three days now and she's doing nothing but partying with her friends having the time of her life. Before she went to Vegas we got into a fight and when she came to see me. She didn't have her ring on her finger.. She said it was because we were fighting and she got mad. But honestly seeing that broke my heart. I trust her so I don't think she'd do anything.... She's has always told me everything but she keeps telling me she can't tell something's because her told her these things in confidence. But she has always told me things before..  I'm really heart broken and I'm not sure what to do. Ever since we moved in with her mom she's been a different person. She's the love of my life and I really need help on what to do. 😞