Well, eventually the tears dry up. I dunno if that's normal for everyone, but I went through a period of time when I was crying nonstop and then I suddenly lost nearly all ability to cry. It's very VERY hard for me to actually cry anymore even though I want to.

But you don't need a reason to be sad and you don't need a reason to cry. You should, however, be seeing someone to figure out the root (if any) for your tears and figure out how to help with medications if necessary.