when a man shows no interest in working on the relationship means he just wants to move on to the greener side of the hill. Perhaps he's found someone else..dont really know the reasons of your arguments but this could be one! 

 So the best thing u can do right now is not think about it and leave him alone.

Where there is Fire...There is Coke. Where there is Rum..There is Smoke - Sir Smoke-a-Lot