Do you have tricks or suggestions for dealing with disappointment?

I’m active in community theater, and a play I had a part in was recently cancelled. Since I was an integral part in the publicity, I had to be the one to deliver the bad news. I had to call the newspaper. I had to paste the cancellation all over Facebook where it was liberally advertised. I had to contact the greater theater community in my area, and I will have to explain what happened to the board of directors of the non-profit theater organization what happened.

How do you deal with severe set backs? How do you handle disappointment? What do you do with the sadness?