In the case of my ex, she would be abusive towards me and all then for a few weeks things would 'get better' and normalize then it would happen again.

Therapy helped me see that cycle of abuse and emotional manipulation i was in. Note she never abused me physically but mentally and emotionally she did. She'd get very angry and yell at me and say its my fault she's angry,aggressive and yelling at me.

There was a period after we broke up where she was threatening to kill me and I was so afraid I carried a gun everywhere I went. I legitimately considered getting a restraining order on her. She went and got mental health help and she takes meds now and is much more stable and better and now we get along at least.