What can be done if I am going through a break up with my girlfriend and we are unfortunately fighting for the apartment we are renting together?

We have been living in the apartment for 6 years and we usually split the rent. I actually pay every month and she reimburses me. I was on vacation last week and while on vacation, she sent me an email telling me things were over that she moved all my stuff downstairs and I should come pick them up whenever I can. She also told me not to come home because she had friend over and to find a place to stay. I did not to my apartment because I traveled for 16 hours and I was just exhausted. It does not seem right that she decide to move all my stuff without my agreement. I really don't want into wars but it seems unfair she decide to keep the apartment. I also paid for most of the furniture inside. I told her I wanted to meet to talk about the apartment and that I was expecting to see my stuff in the apartment at the place they are supposed to be. However, I am not sure how to handle this apartment situation.