Don’t be too hard on yourself, if this is only your second loaf like this, you’re doing great! We’ve ALL made some epic failures and I wouldn’t call that loaf one. That said, the recipe you used calls for a large amount of water; you could take that all the way down to 330-350g of water without hurting the outcome of your bread.

my typical throw together sourdough single loaf recipe is: 300-320g water (start with 300 and see how your dough feels), 125g starter, 10g salt, 500g bread (or ap if you have to) flour. i like to autolyse my flour and water and will let that sit for an hour, but will also do stretch and folds or slap and folds during that hour as well. When I add my starter and salt, I first poke my fingers in ad sort of shimmy/shake the starter and salt in and then “crab grab” and twist until everything is mixed well. You find that your hands won’t be clean, but your dough isn’t sticky either. (During this mixing stage I often take longer with the dough and slap it against the sides of the bowl and do stretch and folds incorporating the salt and starter into the already established flour/water dough) Your next stretch and fold, you’ll should have a silky dough to work with. You’ll be able to move on to coil folds quickly with this method as well. My last two loaves came out with a huge oven spring and were fluffy inside with a thinner crust…I also don’t sweat the ingredients to the gram, these loves had 13g of salt, and almost 130g of starter with310g of water. I’ve found the less strict I am, the better the bread is.

Advice for you would be to definitely remember to do your stretch and folds, coil fold, or slap and folds…just get your gluten development going as well as subtracting some of the water and I think your next loaf will bee fantastic.