First, congrats on making it this far! That's amazing and a huge feat.

Second, no you're not crazy. It is risky, but not crazy. Are there a few things you can do to derisk your decision? Identify what you would need to know to feel comfortable and work back from that to form testable hypotheses. Then figure out how much time/money/effort it would cost to test those hypotheses.

If that seems like too much work, or you still won't have the certainty, I wouldn't go all in, but there's one other option before shutting it down. Can you sell the business? Maybe to a search fund or a small investor? I'd get in touch with Arvid Kahl, here or on Twitter if I were you.

Best of luck!