Her dumping her every thought and issue on you is trauma dumping and you may have created a trauma bond thinking that this sharing was because of a genuine connection, vulnerability and intimacy. Thing is she’s indiscriminate and will do this to anyone who sticks around long enough to listen. You are watching her emotional state unravel and you want to stick around and figure her out, thing is there’z nothing to figure out because she’a not behaving rationally. She’s also putting you in an impossible position by dragging her into her bad decision making by making you her confidant that she’s disappearing from her own life to go back to her abusive ex. There’s no sense in that!

FWIW, I don’t think this is a secret you should keep. She’s putting herself in danger. Being a danger to yourself or others is the literal criteria to be committed for psychiatric care