Sorta Sourdough

I've been trying to develop a sourdough starter, I used a cheat method and put a tiny bit of yeast in the starter and I think that made my sourdough develop really quickly, maybe too quickly and I missed its prime or didn't feed it enough. Not sure what exactally the problem was but this sourdough was so dense that it wasn't edible. I used the recipe I linked here. I used 2 cups of my sourdough starter plus 1/2 cup water, 3 cups flour, 1 tbsp kosher salt, 1 tbsp sugar and 2 tbsp olive oil. I let it rise twice each time for about 4 hours but it didn't rise that much. The directions that I linked to (The John Ross directions) didn't really say much about rising times. The dough was rather wet so I baked it in loaf pans. I think 1st my sourdough starter wasn't active enough and second I didn't let the dough rise enough. Heres the end result.

It wasn't edible. Oh well better luck next time. I have a new starter going that I did not add yeast to, I'm hoping it develops better.