I have kind of the same problem. The difference is that I suffer a lot of anxiety and not so much depression, and that I have cried very little in my life. Not because I didn't need to, but because I always thought I was tougher than I really was, and always ate all the problems and kept them to my self, not letting them be alleviated by cry. Therefore my problems built in top of each other and I felt like my crying capabilities became blocked. Like I couldn't feel anything other than an impersonal suffering so big that crying wouldn't even help. I don't know. Right now I feel like crying would help me, but like you, I am just not able to do so.
I think I know what's important to me. I just cannot help making important what I know is not.