Rae is right. Prepare yourself. It takes time. It'll come in waves. When it used to hit me at work where I couldn't go find a corner and cry, I would pick up a scrap of paper and write or scribble or jot a few words or draw a picture. Anything to release some feelings. Then I'd cry when I got home.
Sounds like you're doing well with NC. That was always so hard for me, until the final time we broke up. Keep that up, and if you don't have a plan for diverting your thoughts when you want to see/talk to him, come up with one.
Phone a friend, go for a walk, do hot yoga, whatever it takes. Or spill your thoughts on paper instead of to him.