That posting is so full of crap that it might actually BE John McCain. In any case, being depressed over the possible loss of a relationship or loved one is not a medical condition, but an entirely appropriate response as a human being.
That's what the grieving process is for, to work all the debilitating sadness out of your system so that you can resume life in a functional way at some point. So reach for the Kleenex, the Hagan Daas, shoulders to cry on, and good friends and family. Forget about doctors, medicines and other substances.
There's no substitute for allowing yourself to grieve. It's the best and most natural emotional cleansing there is.