Don't panic - Right now you need a level head. Take some deep breaths and relax. Lots have gone before you and lived (assuming you haven't done anything illegal or unethical).
Don't throw good money after bad - Once you realize you're not going to make it up in volume; that the cost of each one sold is more than the price the market will pay, STOP. Pause the Google AdWords campaign. Stop the Facebook Ads. Suspend the Twitter Ads. Do it now. A penny saved is a penny earned.
Take stock - What do you have? How much time? Are the errors reversible and do you have the resources to reverse them?
Talk to a mentor - Right now your perspective is skewed. Talk it out. Find someone you trust who provide a clear perspective. It would be best if you know someone who has stumbled and recovered well.
Evaluate your options - What are your resources and how can you best use them? Can you meet your obligations? If not, can you negotiate for some time?
Make a plan - Now it's time to write something down. Generalize the plan and run it by some trusted mentors. Once you've got a reasonable plan in hand start working it. a)define the very next step; b)do the previously defined step; c)rinse and repeat until solvent.
Through it all don't lose sight of what you accomplished and learned. Next time it won't be so bad.
Go, do something remarkable.
