Of course you are sad! Wanting to call him is a normal response but, rest assured, that is the hook that will suck you back in every single time. The best thing you can do at this point is to distract yourself with other activities, turn your cell phone off, go out with a girlfriend...ANYTHING to get you through this tough part. Have a plan for when he DOES call! What will you do? Practice your plan over and over in your mind.
No Contact is by far the fastest route to serenity. Trust me on that.