Why can't I cry..

In the beginning of this journey that I am on, I didn't seem to have any trouble expressing myself. Especially crying, it seemed to really help my mood, they do say "Crying cleanses the soul".
But it seems that the farther I go in this journey, the harder it is to express myself. I try to hide my true feelings of hurt and pain, that I wish would subside at least some. My daughter seems to notice, but I just tell her, I will be fine. She says that I need a good hard cry. Which I truly believe would really help, just wish I knew why I just can't.
I miss my dear Paul so very much, I feel like we were robbed of our happiness and time together, that had just only begun, when it was taken away so quickly.