Stop answering his calls. It’s the only way to end this. Tell the police you are doing it if you fear his reaction and he knows, or you suspect that he might know, where you live. But absolutely do it. No contact is the only way to heal. He will absolutely exploit any avenue to control you, especially now you have left. You have to be strong and close these avenues. Stop answering the calls. Block his number. If he calls from a different number then change your number and only give it to people you trust not to give it to him.
You have left. You don’t have to let him control you now.