The lesson is: don't take on debt. Get investors. If you can't get investors, bootstrap, do some gigs on the side, and use that money to run the company. Then, get investors. If you can't get investors, well, repeat until...

If you do this for a long enough time, and the idea, product, company, team and timing is right, you will be able to get investors. If not, that's the world telling you that it's not such a hot idea, product, company, or whatever. Take the hint.

This is exactly what we did, and are still doing. Unless you hit gold, it's slow as heck. But still, I'd never take on personal debt for my startup.