Am I doing the right thing here? Should I just cut him off completely from my life? Im not sure I can...a part of me still wants to be with him, but deep down I know I cant...how do I make that part that still wants him GO AWAY???
Detachment! Love from a disance.
You need to enforce your boundaries. That is part of leading the MLC'er through the crisis.
Although I seem to get disagreement with this advice, I still believe that we must LEAD. In this case he must choose between you and the OW's. He can not have both.