Regardless of if he would have a diagnosis, he’s acting like he’s been given mixed messages and he’s frustrated.
Looking back, I’ve had to end a couple relationships that denigrated to this kind of drama.
You need to ask yourself if you want anything at all from him. You are saying you want to have a friendship. You are telling him you need a break. That implies you will be back. You are toying with him. He wants you to be his wife. You say you only like him as a friend, and always that was all you felt. You have encouraged him just enough to really mess with his mind. Perhaps you are confused about your own feelings, too.
Those texts he sent are emotionally exhausting. I couldn’t deal with that, if it were me. Do you want a relationship like that? Remember, he does not want to be just your friend and that is what you want. It is not a meeting of the minds. That’s why this is so out of control.