Epic Fail from Natural Starter

OK, I made a sourdough starter and it took me almost 14 days. Looked alive - small bubbles on top, so i tried to make a Casera loaf - The dough seemed a bit dry so I added a little water before using the hook. This recipe calls for mixing 12-14 minutes, then let rise for 2 hours, then work on floured surface to form a ball. Dough seemed pretty floppy but had risen. After than you knead it a little to release rise and then let sit in fridge in bowl lined with floured towel for 6-10 hours. Then bring to room temp and back on pizza stone.

The dough stuck to the towel so I had to pull it off the fabric and try to form back into ball. It was pretty flat by then. I put o n pizza stone and it looks like a giant 2 inch cracker.

I’m pretty sure I did more than one thing wrong - any thoughts?

First things first… A recipe would really help! And if possible photos of the loaf with a crumb shot.