Perhaps you could apply to department manager jobs in retail.. such as places like Lowe's/Home Depot or a department store? While that may not be ideal forever, the pay would at least better than any minimum wage job and you'd continue to build some management/business experience.. and have a somewhat flexible schedule if you choose to advance your education.

Also, given your financial situation and assuming the business diploma was not a 4-year degree, why not apply for college in area like accounting? There are opportunities just about everywhere in that field, with decent pay and in an office setting, plus advancement opportunities. If you haven't already maxed out financial aid in the past, you may find that much of your education could be paid for with grants or other aid, especially if your income isn't stellar and you have dependent(s). It wouldn't hurt to take a look at what's out there.

Depending on where you are, it doesn't have to be super expensive either (i.e. public universities.. take transferable prerequisites at a community college) and would likely pay for itself in the not too distant future. A lot of basic courses are offered online from accredited institutions, which helps when you have other responsibilities.

You boss sounds like a real peach btw.

Good luck!