I don't think it's a lack of communication or understanding since you've been communicating the same things for years. And it's not a matter of not being on the same page. It's not a cognition problem. Does he show cognitive difficulties in other ways? Or just with you?

Bottom line is, the reasons for his treatment of you do not matter. What matters is how YOU feel through your interactions with him.

Do you feel respected? Do you feel heard? Do his actions match his words at all times? Do you feel loved, appreciated, supported, and valued? If your answer is no to each of these questions, then you know at the very least that he is toxic for you. And if your answer is no to each question, then you know that he is abusing you.

He baits you with abuse tactics so that you react and look like the crazy unstable one.