You are not a sitting duck, or a hapless wallflower, incable of making decisions for yourself.
You left a 12 year relationship, for another man that you did not know, that you met on the internet. That was a major decision.
You made the choice to move in with him, and you made further (bad) choices to allow yourself to be under another persons' control.
While the man you chose may be an abusive, manipulative liar, you chose him, beyond any doubt.
You chose to allow him to put a wedge in your entire life, and chose to be a victim. Seriously, meeting a man online, and jumping immediately into a relationship was not the greatest thing you've probably ever done.
You have finally made a good choice, to leave this man, and that choice may very well have consequences of its own. For example, you may need to speak to police for assistance.
Do not leave yourself vunerable, to anybody elses' behaviour- you can no longer predict what a strangers motives are, and this man is essentially a stranger. You do, however, have the benefit of knowing what he is likely capable of, because you have been involved with him.
Seek assistance from friends and family, and try to realize that their understanding of how you are handling this split is indicative of a greater problem.
That is, how to help yourself, effectively, to not only stop unwanted contact from him, but how to stand on your own two feet.
If you are this easily swayed into such a relationship in the first place, I suspect (guess) that you likely have other problems that need addressed too.
Decide NOT to be a victim, learn why you were, and know through learning (counselling for example), how to avoid this potentially deadly pitfall in the future.