Well, I think that the main thing is to do something - anything - to keep your head clear.

Back in 2001-2003, my industry in particular had an incredible downturn and at the time I was self-employed and was having an incredibly hard time finding enough work. But I was able to find grueling manual labor - stuff like shoveling mud out of a flooded basement one bucket at a time and carrying beach-ball sized rocks out of what was the center of an old stone barn that hard partially collapsed - and the remaining gable end walls were too unstable and dangerous for power equipment to get in and haul out the rocks.
I'd work 12 hours hauling rocks and the next day I'd put on a suit and head out to one of my clients for a strategic planning session with the CEO of the company. I did this mix of things for two years, taking on what I could, until things finally picked up again and I was back to my cushy indoor job full time again.
I think that's the key - if you were a CPA and you can't get work, OK, then take whatever work you can get. The only loss of dignity is found in giving up. All these years later I still feel proud of the reaction a friend of my wife's had when she learned that I'd been hauling mud out of a basement - she knew me as a successful business owner up to this point - her reaction was "Good! That's what real men do - they buck up and get the job done".
It should also be noted that I also joined the fire company in 2003, this has, despite my recent issues as posted here, been a very good move for me personally, because each time I work a car wreck, each fire that we deal with, each marine rescue and each body recovery job reminds me that I do more than just my day job, that I have developed a buffet of skills that has proven more valuable over time than any one thing I "do" for a living.