Bryan,
I had the same problem. Accounting degree, but worked as a software engineer for almost 20 years then got laid of in late middle age. As you get older, employers don't want to take a chance on you when they can get younger workers for less money.
My biggest period of unemployment happened just before 9/11. When that hit, I went out to get anything. A week later I was selling plumbing supplies at Lowe's. In a year I had the opportunity, through a friend, to get into something entirely different. Then after two years there building experience, I got into a completely different line of work and I've been at this job (video production) now for 12 years.
I think that's the key is to be flexible to new career opportunities. Keep in touch with all your acquaintances and associates. If you have to take something else in the meantime (like a big box store), keep your eye open for opportunities there, plus befriend all the people you come into contact with.
And the secret to getting a job at a big box store (HD, Lowe's, etc.) Ask to fill out the manual application form. Ask to speak to "the" store manager (not an assistant). Hand him/her the application and say: "I'm willing to work any department, any shift and I will be here on time, ready eager to work for every shift." They are looking for sober, smiling faces and a personal touch goes a long way.