Yes, I'm the same. My therapist has asked me to try and cry when I feel bad, and I want to because it would release the tension. I don't normally have problems crying (should have seen me watch The Colour Purple!) but when I'm tense the tears just won't come. Last week when I was feeling rotten at work I actually went to the ladies' room and really really tried, screwed up my face and all, but nothing. Good thing they don't have cameras in there! ;)
Hope this won't offend anyone (well, it's natural, without it none of us would be here...) but having sex always helps me. It gives me the same feeling of release that crying does.
I think there is a physiological reason for this, if I remember correctly from a class many many moons ago: The autonomous nervous system consists of two parts, the sympaticus and the parasympaticus. Only one of the two can be active at a given time. The sympatic system, using adrenalin as its transmitter, does all the using up of energy, like muscle activity, sweating, making your pulse go faster and constricting your blood vessels. That's the bit that's active when you are panicking.
The other bit, the parasympaticus, using insulin, is concerned with restoring and conserving energy, relaxation, digestion, slow pulse, soft muscles, crying and sex.
I find that for me fear is stronger than appetite, ie when I'm scared I can't eat, but sex is stronger than panic, ie while I'm having sex I'm not afraid. I wonder if fear, at least for some people, is stronger than crying, and therefore while you are scared you can't cry. Conversely, if you managed to cry you wouldn't be afraid anymore, because one is parasympatic and the other is sympatic, thereby cancelling each other out.
Same goes for relaxation techniques, I suppose: if you can manage to get the slow breathing and muscle relaxation going it disables the sympatic reaction.
I'll have a look on the Web for a site that explains this a bit more scientifically.
As always, sorry for waffling!
Marianne