I don't think crying itself is an absolute no no, but it really depends on what the situation is. Crying over the death of a loved one is one thing... it's part of grieving. In the case of self pity, because she doesn't want to be with you, it certainly wont help your situation by crying to her. From her end it would probably sound like groveling, and no one likes whiners who cry because they don't get their way. All I can say is that we live, love, and learn. Don't drag yourself down even further by wallowing in self pity. Sometimes relationships dont work, but we can't control that. You have to pick yourself up and realize that there are far more serious things to cry about in this world than loosing a girlfriend, and eventually if you try, you'll find someone new anyway.