I think one of God’s gift to human beings is the ability of humans to cry. It gives us the ability to overcome loss, mistakes, failure. Life seems worthless at times and you want to end it. There is so much pain that you cant bear it. Things are the way they are and there is not much you can do to change them. However much you want.
The depression hits a new low when you are unable to move on, because there is nothing to move onto. Sitting alone you get negative thoughts. Even when you are surrounded by people you can be the loneliest person in the room. You wish there was someone who you could talk to, someone who would guide you through the turmoil and darkness. But you realize there is no-one and then you realize there is no one because of the way you are. You have repelled people away from you, staying quiet and lonely all along. And now when you need someone to talk to there are none.
At such instances, your life seems meaningless. This is bad as you feel like ending it. After all something which has no meaning should not exist. And then you cry! And all the body releases hormones which make you feel positive, which give you hope. You feel light and you move on.
Crying is a survival technique as powerful as the anti-bodies in our blood. Too much depression can lead to suicide and the body fights this by crying. So if you are feeling depressed and lonely just cry. And move on!