Don't be so hard on yourself. I don't think your degree is useless. Work experience is more valuable than a degree in most cases. Unless you're interested in pursuing a career in a specialized field, I'd stay away from an MBA. And even if you are.. I'd say it's probably not going to be worth it when you consider opportunity cost.

Figure out what kind of work you're interested in. Given that you just want to be able to pay the bills, that leaves you a heck of a lot of options. Then, go out and do some professional development in that field. That means the simplest certifications you can find. In almost any area of business showing that you're committed to efficiency, process improvement, and eliminating waste is an attractive entry on your resume. A Six Sigma belt certification would help to supplement your work and academic experience.

Overall, be proud of what you achieved. You can pretty easily highlight the ability to keep a used car dealership alive in the age of Carmax and Craigslist as a positive. Be prepared to talk about your skills, complete with examples of how you've used them. Running your own business is unique, and gives you perspective into day-to-day activities that other applicants are not going to appreciate.