I Have Always Been Upbeat And Positive, Until Becoming Ill

I have always been upbeat and positive, until becoming ill a few yrs ago that forced me into early retirement.
The separation of work friends and lower income has pushed me over the edge. I think of just during and
ending it all, but I realize this is not the right solution, I'm on 100 mg of sertaline a day. It just helps a little, perhaps a placebo affect. Any suggestions.