First of all, yes - realizing after MLC that they are a different person is one part of it. Your STBXH is completely different than the person you knew and loved. And - as you said - a limit was crossed.
You will find freedom from all of this. It was tough for me at first, but I have found it as well as happiness. My XW started seeing my XBIL just months after being S - she just married him last month - just 1 year after the D was final. I think she still suffers from MLC and your STBXH maybe too. It won't be til much later that they realize just the wreckage they have created.
Good for you that you won't allow yourself to become that wreckage. I know it has been a while, but you are a great person and one that truly deserves all the happiness in the world. As I said, peace will come and you will find your way back to happiness.
I hope you are feeling good and take care. I will find you over in Surviving.....
