Why does life have to be so hard? Why is love not enough?

Adam's birthday was last week. I did ok on that day. I guess I had prepared myself, but the day after and the days since have been hell. I can't quit crying. I try, I tell myself it doesn't change anything but I can't stop. People tell me to remember the good times but the good times are often more painful. They are just a reminder of what we are missing and will never have again. Life just goes on. And that life is not one I recognize, not one I thought I would have to live. So how do I do this?