Complete no contact is the way to go. He doesn't have a right to have a relationship with you even if you are the 'love of his life'. Block the number, delete the texts, and if he gets through on another number that isn't blocked, just hang up as soon as you know it's him.
Harassment is not love. Stalking is not love. Calling 100 times a day is not love. Love is very different.
He's trying to force you into being what he wants you to be, ignoring what you are. That's not love. If he loved you, he'd let you go. He can't let you go because he believes he owns you. It's not the wild destined passion of a soul mate. It's the cruel determination of a man who insist he's going to crush you into his ideal by willpower and whatever else he can come up with.
Every day you he doesn't hear your voice or gets a response from you, is a day you win. Suddenly after a while, you will have gone so long without communicating with him, you will feel sick at the thought of it. It won't be hard any more.
As soon as he finds someone else to cater to his neediness, he'll drop you like a hot rock. Until then, hold firm and don't respond. Can you turn off your phone so don't even know he's trying to get in touch and just use it to make out-going calls? Or can you put it on silence in your bottom drawer, and then get a cheap pay as you go go-phone for use with you and trusted friends? He'll keep calling the old number, but you won't know...
It'll be easier on you.