You may think that communicating with a person the other side of a computer screen (or how ever you are communicating) is not the same as chatting with a friend face to face, but I would like to encourage you to share as much of your story as you need to here. I care for you as do Geoff and White Knight and possibly others who have read your thread but not posted anything.
One great thing is you can share all you want to here and it will be between us and you! None of us know who you are, or where you are, so you can write all you like.
I do understand not wanting to share with your friends at work, that would be a little awkward. I hope your encounters with this guy are not too traumatic or confusing for you. I know you probably don't like the saying "IN TIME" as I know I myself have cringed when people have said it to me. But in time, down the track in months to come, maybe you will be back on friendly terms with this guy, having a brief chat and a Hi as you pass each other. That might not be the case either.
For now you need to look after yourself, build up those friendships and spend some special time with your fiancé and child, so you know just how blessed you are in life to have them.
You are incredibly strong and resilient to be able to stay at the same work place, to want to try to make the most of the situation and to be brave enough to share your story with us all here.
I used to bottle stuff up for years and it really isn't a healthy option! I have a wonderful friend whom I can email just about every aspect of my life, the good, the bad and the ugly and know there is never any judgement or criticism, just an acknowledgement of what is happening and how it makes me feel, plus some kind advice on how to cope and move on.
Congratulations to you for being able to share your story with us. I do so hope it helps, and you will continue to let go of what is painful inside of you.
All the best, from Dools