sad

I'm unbelievably sad today.  It's not the kind of depression that makes me so low that I nearly feel numb to life around me.  It isn't the kind that feels so hopeless that I cannot function.  It is just the kind that longs for a bubble bath and a really long cry.  The problem is that I don't even know what I want to cry about and I don't feel any tears behind my eyes waiting to slip from my eyes to roll down my face.  How can I feel an overwhelming sadness and not have a reason to be sad or a way to let the sad out?  Oh the joys of major depressive disorder and the effects it has on living life.  And the really sad part is that my medicine is actually helping and yet I still feel this way.