My ex will not leave apartment.

I 25M and my ex gf 23F broke up about 2 weeks ago. She broke up with me and at first she talked about leaving asap. However, she plans to move out of California where we rent and go to another state. I figured she wants to be here for a month tops while she looks. However, she said she has a Spartan race she wants to run in April and for that reason she will not leave for at least 2 months. Our lease expires in September so its not anytime soon to just wait. But she hasn’t given me a time frame. We both agree that I can afford rent on my own and she cant which is why she is leaving. But she constantly talks down on me and says I was one of the most selfish dishonest person she’s ever met. The relationship is over but she constantly reminds me how bad I screwed up and what I lost. I get it.. so then leave I tell her. You want to stay a whole extra month for a race. But she won’t sign an agreement or anything nor give me a solid date and its been like 2 weeks. She also threatened to sue me if I tried to get out of the lease myself and leave her with a burden. Also vaguely hinted about suing for supposedly promising her that I would marry her and causing her emotional pain. I feel so trapped and have no idea what to do.