I hope you dont mind, but THIS particular bit of your post leapt out at me.
Take whatever he took from you back. RIGHT NOW. I know you have only alluded to what actually happened, understandably, but from my own personal experience, the only way to really recover from such an incident is to recognise that it was out of your control, and to be able to put it behind you, you need to regain that control for yourself.
Acts like that are not about the act itself, they are acts of anger, of control, of feeling the power over the victim. The way to win the fight is to not take it personally, (ridiculous as that might sound, it really isnt a personal attack on you, your character, your looks, your personality, any of those things) - it is quite simply and plainly one human being wrongly exerting control over another and intimidating them.
So dont let him. I know that sounds easy for me to say when you are finding yourself seeing him in person, but you are in a safe place at work, with people around you - he cannot do it again and allowing him the power to scare you is just not giving you the credit for how far you have come in recovering.
If you can get it into your mind, that it happened, it wasnt personal, it is over, you survived it and you REFUSE to allow him to have any more influence over your life - you can really make a difference in how you feel about yourself. Its not always easy, but you just keep reminding yourself of that. Allow him NOTHING of you. It wasnt his to take and he just cannot have it. Its YOURS, and you are having it back.
(((hugs)))