I was desperate (in a depressed, "this life isn't worth living" way) over the summer because of a health condition. I managed to fix it, but I wouldn't say it was optional in the sense that it was about a story I was telling myself that I could change at will. I wasn't able to just snap out of it with application of the proper workshop or talk therapy. In fact, that was precisely why I knew it was a health condition, because I can usually change my mood at least a little bit by changing my way of thinking and/or my habitual behavior.
I did learn something from that, though, which I can apply now that I'm out of the desperation part: when desperate (which means "without hope,") go ahead and be desperate, and simply move one slow step at a time in a direction that looks like it'll be different from where you are now. Why not - you're without hope, so you have nothing important to lose.
The deceitful face of hope and of despair
Deleted my OKCupid account because they are trying to get people to use their "real names," whatever those are. Apparently they aren't going to…