Wiz - It is a lot to think about and can easily become overwhelming. I can definitely see where having an MBA will give you more opportunities for a sit down type job in the future. And I do think you should plan and continue your education as education always pays off in the end.

Can you switch to part-time work at the store?
Can you stop working and just focus on school?
Can you find something that is home-based and work from home? (That's what I do and for me it has been a blessing)
Will taking the classes every other eight weeks make that much of a difference? Thirteen months vs 26 months?

These are just some questions that I would ask if we were sitting down and talking about it. I would make a list of pros and cons as well as what you feel you need to do. Listen to your intuition. It's telling you something, just pay attention to it.

I know that you will make the right decision for you. And, as others have posted, you are amazing!!! I admire you greatly for all that you do.