I'm having one of those nights when I miss him like crazy too. I know better. But it sure hurts.
Mine left me, not the other way around, so I have no control. He went NC on me and told me never to contact him again. It is beyond me how he can not miss me at all. I am in so much pain some days, and it's been 22 days. I hope it gets better soon.
It's such a conflict of feelings. Missing someone and being mad at them and wondering if they even give a damn about you anymore. I left my ex and went NC, almost a month later out of the blue she texts me telling me she hates me and to never contact her again. Then two days later how wonderful I am and how she loves me but that those will be the final words she says to me.
And here this whole time I was hoping she would text me that she misses me and she wants me back and blah blah blah. Nope.
It does get easier. One month was a real turning point for me. I miss her less, but for some reason I find myself sad more often. I think this is because it's finally sinking in that there is a good chance she really never will contact me again and it's finally done for good. Hurts pretty bad but there's light at the end of the tunnel: a more level and happy life!