Man, that happens to me once a week in correspondence chess! Always against much weaker opponents, too, so my rating suffers.
Human Blunder Check

I don't like the game of chess right now.
We've all blundered away winning positions. Reactions can vary, though. When I throw away a game I still like chess-- I just don't like myself.

Happens to all of us ... for dangerous positions where I'm winning but don't want to lose the thread 3 days later, I scribble out "watch out for _____" notes in my notes tab just for this reason. :)

That's one thing that sucks about CC -- in live or OTB you can get on with it and lose, or just resign, and hopefully forget about it soon enough. In CC it's sitting there, hanging over you head, reminding you of your terrible blunder. It can be pretty depressing That's one reason (although not a main reason) I don't really get into CC.

That's one of the things I really like about CC. I write up summaries of a lot of my losses (I've posted some on my blog), keep my games notes, and review them if I've got similar openings underway. What can I say-- I revel in phailure!

That's one thing that sucks about CC -- in live or OTB you can get on with it and lose, or just resign, and hopefully forget about it soon enough. In CC it's sitting there, hanging over you head, reminding you of your terrible blunder. It can be pretty depressing That's one reason (although not a main reason) I don't really get into CC.
Throwing away a won cc game after 28 moves, several days having passed, the time invested - you just wanna have one too many beers or something. It's the only thing that makes sense right now.
I may switch to bullet chess for a while. I'm not sure if I could even handle blundering in a short 5-10 minute blitz game in my current state of mind.

It's interesting how out of all of my games I can only remember one time where I lost a clearly winning position (up an exchange) when playing cc chess. I have drawn some, but not lost them. In otb and especially blitz this is a different story. At the same time there have been very few times where I could come back to win a lost position.
Comebacks aren't so common in CC.
Does it exist?
I just tossed a winning game away in a 3 day per move correspondence chess match and will shortly be checkmated. For sake of time for both sides, I'll resign in just a move or two. I was so focused on a nifty game winning combination that I went into auto-pilot on one move and made a game losing blunder.
I don't like the game of chess right now.