Tears

why can I not cry?? There seems to be something that is preventing me from crying these days even though I desperately want and need to.. I cannot seem to get that relief. I would love the release short lived though it may be of a few tears. truth be told I have not ever been a crier. I have been a bury it and move on. Now my emotional landfill seems to be overflowing and I am barricaded from doing anything with it. I become irritable and snippy and take it out on people who do not deserve it. I would love to just sit and let tears flow why can't I?? Why? Tense. Tired. all of it but no more tears. Why??