I don't think you have failed. I think your strategy has failed. Maybe a better strategy would have been to still have your job (part-time?) and still have a visa and then use the rest of the time to create your product. You might use a lot more time, but the great thing is that you always have something to fall back to (the chance of failure is huge when doing startups so it's good to have some kind of safety net). When/if your product starts to take off then you can then quit your job and apply for a entrepreneurship visa. I think it's a much more sane strategy than risking everything.