Oh goodness, yes you still are attached, aren't you. You have had a lucky escape in getting away from this man in the first place, but the problem is that he has left a wound that isn't healed yet.
I strongly recommend you seek counselling if you haven't already had it because you need to a) realise that you are worth more than this man, and b) realise that what he felt for you wasn't love, it was power. Power over you. He may feel exactly the same way about the woman he has just married, he may not - but that doesn't matter because she is someone else, and what happens between them is irrelevant to you.
HE should now be irrelevant to your life except as a piece of your personal history. The fact that you're even thinking "that should have been me" shows how interlinked you still are with him, and that is something you need to resolve.
You're still giving him far too much power over you - by feeling this way, by thinking about what might have been, by wondering about his feelings - stop thinking about him. HE IS IRRELEVANT NOW.
You are worth so much more.
You deserve someone who will treat you properly, who will love you as you are.
You deserve to be loved.
You deserve a life without him in it.
The Freedom programme might help you too.