Of course you miss him. That is natural, it's going to happen! It's what you do about missing him that will make this better. Did you know that activity trumps an aching heart?? True story!
I don't want you to think that I decided one day to be dark and never looked back, never stumbled, never cried. I did all of those things - over and over sometimes. In darkness, I handled them different, though. I didn't give in to the urge to grab the phone and call him about some mundane thing just to get him on the line, I didn't write another goodbye letter (I had a lot). I had to do other things to get through it.
Hang in there, you're doing great!!!!
Heck, if you need to get some aggression out there are a lot of outlets on the board at the moment....
"It is not easy to find happiness in ourselves, and it is not possible to find it elsewhere."
--Agnes Repplier, writer and historian