Im very worried about how you keep referring to how you will HAVE TO do certain things rather than hold your ground
If your manager asks about leaving, you will HAVE TO leave rather than say 'no, Ive changed my mind about that'
If he gets into trouble, or says you are cruel you will HAVE TO get back with him to somehow pay for your behaviour.
You do know that nobody can make you do anything you dont want. They can scream, shout, cry, throw themselves at your feet, but ultimately YOU are in charge of your own destiny - you are not flotsum being blown from here to there on the waves of life.
You can be as cruel as you like in breaking up with someone. Im not sure you particularly were, but it seems to be the fix that holds, and he is using to guilt trip you.
You dont owe anyone a relationship. Even if he shouts it from the rooftops and puts a full paid ad in the Times, you dont owe him a relationship. How he is behaving towards his family, is HIS choice. You have made it clear you are over and you dont want him to tell his wife, but if he chooses to, thats his choice, and you STILL dont have to open the door and let him in.
You should have phoned the police.
You need to go to HR now, and someone official needs to tell him that he is not to contact you. Using the work phone/email for this is unprofessioanl anyway. And he mustnt come near your home or you will call the police.