Wow, what a dreadful situation.
I do not know the economic situation in your part of the country. I do know that much of the midwest is experiencing a huge downturn economically. Also, we are in the middle of the 2nd worst economy in the modern era, only the Great Depression was worse. (And I believe that the Great Recession may prove worse in the long run as the type of economy is changing while during the Great Depression, the kind of economy - industrial mass production - did not change. Anyway, my historical wonderings do not help right now.)
I know lots of people who have done everything right, busted ass, got new degrees or training, networked like mad, and are still unemployed, underemployed or trying to make a business go. So give yourself a bit of break. It is objectively very, very, very bad right now to get a job.
However, more specifically, what would make you happy? You talk a lot about making your wife happy but never write what you would want for yourself. You deserve to be happy too. What would that look like for you?
There is a saying in poly that adding people to a broken relationship does not fix that relationship. It's still broken, just with more people. Your marriage is broken, I'm sorry to say. Adding the new guy won't solve the problems in your marriage and developing a quad would just bring more people into the craziness.
I'm also sorry to say that it reads like your wife has checked out of your marriage. She's done but for whatever reason won't do the honorable thing and divorce you. It seems to me, and just my opinion based on what you wrote, that she is pushing you to divorce her.