Do I come across as like a woman in love
In all honesty, you sound ridiculously jealous and are behaving obsessive over someone you had nothing with and as though you are a victim of some cruel act by him.
You enjoyed the chase and attention despite being in a relationship and fail to see anything wrong with your own actions, but once he moves on and wants to be serious with someone he is a sleaze? How exactly, because he's no longer boosting your ego?
You are over-reacting and he is certainly not being insensitive, good on him for prioritising the woman that he is actually in a relationship with. Here's hoping you do not attempt to cause issues for them. If he asks you for any recommendations you can say you unfortunately do not have any suggestions, you are not obligated. As for him discussing his relationship - that is his business. He's made his boundaries clear and appears to be happy with this woman.
You have said you have left an abusive relationship, perhaps it's time you focused on your boundaries and working on your self esteem before you consider dating again. Understand and work through any issues the abuse may have had, that will certainly help you in the long run.
As for him, stop seething, let him live his life. He has not wronged you.