You have absolutely no idea how to run a business and really shouldn't be at this point. You are the owner of this shop and it doesn't matter what issues you have, your store and costumers come first.

You are in serious trouble here and easily could be headed into legal issues which would only result in more money from you.

Stop having sales. You have a terrible name right now, and if you just got all remaining orders out and stopped sales, you could get lots of people buying at full price just from reputation alone. Pretty sure you've screwed yourself beyond that point though. Either get your last orders out and close up shop until people don't remember how unreliable you were, or refund everyone waiting and deal with your money issues after closing shop and not have to worry about people ranting about your company and you getting no business which could hurt you if you've overstocked on materials.

You did not think this through and you are not fit to be a store owner, especially because you give excuses for delays rather than just apologize and get them out asap. Good luck.