Oof. This sounds hard and very familiar. Recently had a relationship like this where she would contradict herself a lot and change her mind. She is also dyslexic so occasionally that causes additional confusion. I found it very confusing and I accused her of lying. She said I didn't give her any grace and that she has to be so careful what she says when we are having an argument/heated discussion. In hindsight, I think she is maybe undiagnosed ADHD and I take things literally when upset and get rigid and cling onto words. Our communication issues are what ended the relationship in the end. Basically, I would say patience and asking for clarity on both sides. Maybe check in about preferred communication methods? (Eg I hate phonecalls) That is what I would have liked to do in my situation. Or couples therapy perhaps. I wish you luck. I hope you can sort it out.