My Boyfriend’s alter hates me

So recently, my boyfriend has formed a new alter (for clarification, my boyfriend has DID and I don’t, and I’ve known he has DID for a little under 2 years), and the new alter hates me. She seems to come out mostly when my boyfriend is irritated, however sometimes she comes out at seemingly random times. She has expressed her dislike to me, insulted my weight, my personality, etc. I really don’t know how to deal with this, I’m already in a really dark place and she’s taking a toll on my mental health. Has anyone else had experiences like this?