He is manipulating you.
He is horrible to you most of the time, belittling, picking at you, making you doubt yourself, making you feel unreasonable, making you feel stupid etc.
Then when he is not even actually nice just... not horrible... for a brief while, for you, thats a MASSIVE relief, it feels great... but it ends very quickly and he will blame you for that, it'll be your fault he's horrible again...
And round and round the cycle goes, damaging your mental health, your confidence, altering your behaviour more and more.
Look back through this thread - how many times has a poster here accurately predicted the sorts of things he will say and do?
We can do this because its a recognised pattern of behaviour from an abusive man trying to manipulate and control a woman because it makes him feel good to do that.
If he has an app that can mask his real phone number, then get yourself a new sim, new number and use that for a while. Agree with him, he was right, it IS over and then change the sim so he cannot get hold of you that way.
He doesn't love you - he can't. He isn't capable of it. YOu can't change him because he does not want to change, he LIKES being the way he is and he ENJOYS hurting you.