just do it one day at a time. each day you wake up, pretend that was the day you went NC and do that each day. you will soon rack up the days of NC and start to at least rationalise things and give your mind a chance to regain some strength. the pain will be there and it will be immense, but do this each day and you will be able to stick to NC........the temptation will be so great to leave NC, but you have to stay strong. I'm in day 11 of NC and although it has been a killer, it has given my mind a chance to regain some control over my own thoughts.
the loss and pain are still there, but i am inching forward in my head at least.
the problem i have found is that each day seems to take forever.......you lose your sense of time and it feels like you are running out of time to do something to save yourself or the relationship. But in reality, one or two weeks is such a short space of time and the world won't change for you in that time. Try not to panic.